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Research projects

Status: 09.12.2024

Content

  1. List of ongoing research projects sorted chronologically
  2. List of completed research projects sorted chronologically with links to 4.
  3. List of completed and ongoing research projects sorted by topic with links to 4.
  4. Brief description of completed and ongoing research projects (accessible via the links in 1. to 3.)

List of ongoing research projects sorted chronologically

The following list of ongoing projects is sorted chronologically according to the respective project start date. Flollow the links for detailed project information.

2025

2024

2023

2022

2021

List of completed research projects sorted chronologically

The following list of completed projects is sorted according to the respective project start date. Follow the links for detailed project information.

2021

2021

2020

2019

2018

2016

2015

2014

2013

  • TUHH project "Soil erosion at riverbeds" from 2013 to 2018
  • TUHH project "Formation of sealing connections in the stretch of waterways" from 2013 to 2015
  • DFG project GR 1024/9-3 "Finite Element based multicriteria numerical optimization of geotechnical structures at sevicability state (FEMNOG)" from 2013 to 2015
  • DFG project GR 1024/11-2 "Influence of capillarity on the mechanical behaviour of non-cohesive soils under highly dynamic loaded logistics areas" from 2013 to 2015
  • LKNM-SH project "Scientific support of dike raisings" from 2013 to 2015

  • BAW/WSV project "Feasibility study for the construction of a test dike as a preliminary investigation for the research and development project 'Determination of the resilience of dikes'" 2013

2012

2011

2010

2009

2008

2006

2005

2003

2002

2001

1999

List of completed and ongoing research projects sorted by topic

The Institute's completed and ongoing research projects are sorted by topic below. 

Soil mechanics and soil dynamics

Geotechnical engineering

Marine Geotechnics

Optimization in geotechnical engineering and construction management

Use of near-surface geothermal energy

A description of the research projects is available via the links to the ongoing and completed research projects

Numerical simulation of soil compaction with vibratory rollers

Status: 28.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 1999 to 2003 (48 months)
  • Researcher: Dr.-Ing. Martin Kelm
  • Status: Completed project, PhD thesis published in institute's series (Vol. 6)

Project description

Numerical simulation of the surface compaction of the soil with vibratory rollers based on the Finite Element Method (FEM). Simulation of the passage of vibratory rollers and the associated compaction of the soil with dynamic deformation analyses with explicit direct time integration and use of hypoplastic material models for the soil.

Project-relevant publications

  • Kelm M. (2004): Numerische Simulation der Verdichtung rolliger Böden mittels Vibrationswalzen. PhD thesis. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 6
  • Kelm M. und Grabe J. (2004): Numerical simulation of the compaction of granular soils with vibratory rolers. In: Proceedings of International Conference on Cyclic Behaviour of Soils and Liquefaction Phenomena, Bochum, Germany, 661-664, edited by T. Triantafyllidis, Balkema, Rotterdam
  • Grabe J., Kelm M. und Mahutka K.-P. (2003): Zur Modellierung der Verdichtung rolliger Böden.In: Veröffentlichungen des Arbeitsbereiches Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 5, 83-107
  • Kelm M. and Grabe J. (2003): FE-simulation of soil compaction. In: Proceedings of 13th European Conference on Soil Mechanics and Geotechnical Engineering in Prag 2003, Czech Geotechnical Society
  • Kelm M. (2002): Anelastische Wellenausbreitung bei der Bodenverdichtung. In: Tagungsband zur 27. Baugrundtagung 2002 in Mainz - Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', S. 51-51, Deutsche Gesellschaft für Geotechnik

Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Experimental and numerical investigation of jet grouting

Status: 28.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 1999 to 2001
  • Researcher: Jürgen Stein
  • Status: Completed project, PhD thesis published in institute's series (Vol. 8)

Project description

Experimental investigation by means of physical modelling (1g model tests), and numerical investigation by means of Finite Volume Method (FVM)  of erosion of non-cohesive soils due to impact of a water jet (jet grouting).

Project-relevant publications

  • Stein J. (2004): Experimentelle und numerische Untersuchungen zum Düsenstrahlverfahren. PhD thesis. Technische Universität Hamburg-Harburg (TUHH),  Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 8
  • Grabe J. und Stein J. (2003): Abschlussbericht zum DFG-Forschungsprojekt GR1024/1-1 "Grundsatzversuche zum Düsenstrahlverfahren". Technische Universität Hamburg-Harburg (TUHH), Arbeitsbereich Geotechnik und Baubetrieb
  • Stein J. and Grabe J. (2003): Jet grouting model tests and simulation. In: Proceedings of 13th European Conference on Soil Mechanics and Geotechnical Engineering in Prag 2003, Czech Geotechnical Society
  • Stein J. (2002): Untersuchungen zum Düsenstrahlverfahren in einem Halbzylinder. In: Tagungsband zur 27. Baugrundtagung 2002 in Mainz - Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', 28-28, Deutsche Gesellschaft für Geotechnik
  • Stein J. und Quillfeld M. (2000): HDI-Halbsäulen zur Abdichtung einer aufgelösten Bohrpfahlwand. In: Beiträge zum 15. Christian Veder Kolloquium der TU Graz, Heft 7
  • Stein J. (1999): Bohrabweichungsmessungen bei der Herstellung einer Düsenstrahlsohle. In: Tagungsband zum Workshop Messen in der Geotechnik, Mitteilungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 62, 209-222

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Fundamental tests on jet grouting

Status: 28.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/1-1
  • Duration: 2001 to 2003 (24 months)
  • Researcher: Jürgen Stein
  • Status: Completed project, PhD thesis published in institute's series (Vol. 8)

Project description

The jet grouting process is used for underpinning structures and for creating waterproof bases and walls. A high-pressure, high-energy jet erodes the soil and mixes it with a cement suspension. The effectiveness of the process is determined by the machine manufacturing parameters and the subsoil. At the TUHH, the erosion process was investigated by means of physical modelling (1g model tests). During the jet grouting process, the jet propagation was measured using an extensive measurement programme. The results were used to develop a hydrodynamic-mechanical model, which was added to the Finite Volume Method (FVM), and implemented in FVM-code COMET. These investigations focussed on the influence of the process on the geometric boundary conditions in the subsoil in terms of the jet shadow problem or the connection to existing structures.

Project-relevant publications

  • Stein J. (2004): Experimentelle und numerische Untersuchungen zum Düsenstrahlverfahren. PhD thesis, Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 8
  • Grabe J. und Stein J. (2003): Abschlussbericht zum DFG-Forschungsprojekt GR1024/1-1 "Grundsatzversuche zum Düsenstrahlverfahren", Technische Universität Hamburg-Harburg (TUHH), Arbeitsbereich Geotechnik und Baubetrieb
  • Stein J. and Grabe J. (2003): Jet grouting model tests and simulation. In: Proceedings of XIIIth European Conference on Soil Mechanics and Geotechnical Engineering in Prag 2003, Czech Geotechnical Society
  • Stein J. (2002): Untersuchungen zum Düsenstrahlverfahren in einem Halbzylinder. In: Tagungsband zur 27. Baugrundtagung 2002 in Mainz - Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', 28-28, Deutsche Gesellschaft für Geotechnik
  • Stein J. und Quillfeld M. (2000): HDI-Halbsäulen zur Abdichtung einer aufgelösten Bohrpfahlwand. In: Beiträge zum 15. Christian Veder Kolloquium der Technischen Universität Graz, Heft 7
  • Stein J. (1999): Bohrabweichungsmessungen bei der Herstellung einer Düsenstrahlsohle. In: Messen in der Geotechnik, Mitteilungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 62, 209-222

Link to list of ongoing research projects
Link to list of completed research projects

Load-bearing behaviour of quay walls in the servicability state

Status: 28.11.2024
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Link to list of completed research projects

General data

  • Funding: Hamburg University of Technology (TUHH), Hamburg Port Authority (HPA)
  • Duration: 2001 to 2003 (TUHH), 2003 to 2004 (HPA)
  • Researcher: Björn Mardfeldt
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 11)

Project description

For the economic and safe design of quay systems, the interaction between the structure and the ground must be taken into account. Quay facilities usually consist of a solid concrete structure founded on piles and secured with inclined anchors. Due to the tide-dependent water levels, the distribution of water and earth pressure on the quay wall is time-dependent. The following investigations are being carried out as part of the project:

  • model tests to investigate the tide-dependent earth and water pressure, 
  • two-dimensional mechanical-hydraulic coupled analyses with the FEM to investigate the transient seepage flow in the near field of quay systems, 
  • three-dimensional deformation analyses with the FEM to predict the load-deformation behaviour of the CTA quay system, taking into account production-related effects.
Figure 1: 3D FE-model of the CTA quay wall in Hamburg, Germany Figure 2: Detail of the 3D FE-model

Project-relevant publications

  • Mardfeldt B. (2006): Zum Tragverhalten von Kaikonstruktionen im Gebrauchszustand. PhD thesis. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 11
  • Grabe J., Mardfeldt B. und Mahutka K.-P. (2006): Zur Lastabtragung von Pfahlkonstruktionen im Hafenbau. In: HANSA, 143(2):42-51
  • Mardfeldt B. und Grabe J. (2005): Nichtlineare Finite-Elemente-Analyse zum Tragverhalten einer Kaimauer im Gebrauchszustand. In: Bauingenieur, 80(9):402-412
  • Hügel H.M. und Mardfeldt B. (2005): Räumliche FE-Analysen für Kaianlagen. In: Bericht der wissenschaftlichen Projekte auf dem HLRN-System 2003-2005, Seite 111-112, Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen (online unter www.hlrn.de/pr/veroeffentlichungen/HLRN-Report-2005.pdf)
  • Mardfeldt B. (2005): Analyse des Tragverhaltens der Kaimauer Containerterminal Altenwerder. Tagungsband zum Workshop 'FEM in der Geotechnik - Qualität, Prüfung, Fallbeispiele' 2005 in Hamburg, Veröffentlichungen des Arbeitsbereiches Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 9, 121-146
  • Mardfeldt B. (2004): Zur Bemessung von Kaimauern tidebeeinflusster Hafenanlagen. Tagungsband zur Baugrundtagung 2004 in Leipzig - Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', 53-53, Deutsche Gesellschaft für Geotechnik (DGGT)
  • Grabe J. und Mardfeldt B. (2004): Schrägpfahlbeanspruchung durch Aushubentlastung. HANSA, 141(5):64-67
  • Mardfeldt B. und Grabe J. (2004): 3D FE-Analyse zum Container Terminal Altenwerder mit Vergleich. Tagungsband zum gemeinsamen Kaimauersprechtag der Hafenbautechnischen Gesellschaft Hamburg und der TUHH, Veröffentlichungen des Arbeitsbereiches Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 7, 151-177
  • Grabe J. and Mardfeldt B. (2003): Tide influenced water and earth pressure distribution on quay walls. Proceedings of 13th European Conference on Soil Mechanics and Geotechnical Engineering in Prag 2003, 693-698, Czech Geotechnical Society
  • Grabe J. and Mardfeldt B. (2003): Tide influenced water and earth pressure distribution on quay walls. Proceedings of 13th International Harbour Congress in Antwerpen, Belgium, 207-214, Technologisch Instituut VZW

Link to list of ongoing research projects
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Traffic-caused vibrations in the subsoil - field measurements and numerical simulation

Status: 28.11.2024
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General data

  • Funding: Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany
  • Duration: 2002 to 2006 (48 months)
  • Researcher: Thorsten Bierer
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 13)

Project description

The German Electron Synchrotron (DESY) in Hamburg planned the construction of the linear accelerator TESLA. As part of this project, the movements of the planned tunnel due to microseismic and traffic-induced vibrations were investigated. In the area of the route of the linear accelerator, DESY carried out seismic investigations to measure ground movements.

Projektrelevante Publikationen

  • Bierer T. (2007): Bodenschwingungen aus Straßenverkehr auf unebener Fahrbahn im Zeitbereich - experimentelle und theoretische Untersuchungen. PhD thesis. Technische Universität Hamburg-Harburg (TUHH),  Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 13
  • Bierer T. and Bode C. (2007): A semi-analytical model in time domain for moving loads. In: Soil Dynamics and Earthquake Engineering, 27:1073-1081
  • Grabe J. und T. Bierer (2006): DESY-Abschlussbericht. Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Bierer T. und Grabe J. (2006): Bodenschwingungen aus Straßenverkehr auf unebener Fahrbahn am Beispiel des Standortes DESY. In: Tagungsband zur VDI-Fachtagung Baudynamik, Kassel, VDI-Berichte Nr. 1941, VDI-Verlag GmbH, Düsseldorf, 569-583
  • Grabe, J. and T. Bierer (2005): Measurements and numerical analysis of ground vibrations at DESY-Hamburg. In: Proceedings of Eurodyn 2005 'Structural Dynamics', Editors Soize, C. and G. Schueller, Millpress, Rotterdam, Vol. 1, pp. 635-64

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Compaction of non-cohesive soils due to dynamic pile driving and due to surface compactors

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2003 to 2007 (48 months)
  • Researcher: Klaus-Peter Mahutka
  • Status: Completed project, PhD thesis is published in institute's series (Vol. 15)

Project description

The focus of the project was the investigation of the intentional and unintentional compaction of soils under cyclic and dynamic loading on the basis of numerical modelling. For this purpose, plastodynamic FE analyses with direct explicit time integration were carried out. The numerical investigations included the following boundary value problems: (1) Compaction of soils with vibratory rollers: The compaction success depends on the machine parameters, the soil parameters and their homogeneity.(2) Compaction of soils with new types of compaction equipment: Optimization of the compaction effect through design measures. (3) Driving or vibrating components into the ground—assessment of the penetration speed and vibration propagation as a function of the machine parameters and the subsoil conditions.

 

Figure: Axisymmetric FEM model to simulation pile driving into the subsoil

Project relevant publications

  • Grabe J., Henke S. und Mahutka K.-P. (2009): Numerische Untersuchungen zur Wirkung von Rammarbeiten. VDI-Berichte Nr. 2063 (Baudynamik), S. 593-611
  • Grabe J., Henke S. und Mahutka K.-P. (2009): Numerische Untersuchungen zur Wirkung von Rammarbeiten. VDI-Berichte Nr. 2063 (Baudynamik), S. 593-611
  • Mahutka K.-P. und Henke S. (2009): Numerische Untersuchungen zur herstellungsbedingten Tragfähigkeit von Pfählen. Tagungsband zum Pfahlsymposium 2009, Veröffentlichungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 88, S. 471-492
  • Mahutka K.-P. (2008): Zur Verdichtung von rolligen Böden infolge dynamischer Pfahleinbringung und durch Oberflächenrüttler. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 15
  • Grabe J. und Mahutka K.-P. (2007): Übertragung von nichtlinearen Schwingungen an der Kotaktfläche zwischen Struktur und Boden. VDI-Berichte Nr. 2022, S. 87-97
  • Henke S., Mahutka K.-P. und Hügel H.M. (2006): Simulation der Pfahleindringung in den Boden. HLRN Nachrichten Nr. 2, S. 3-4
  • Mahutka K.-P. and Grabe J. (2006): Numerical prediction of settlements and vibrations due to vibratory pile driving using a continuum model. Proceedings of International Symposium on Vibratory Pile Driving and Deep Soil Vibratory Compaction, TRANSVIB 2006 in Paris, edited by Gonin, Holyman and Rocher-Lacoste, Laboratoire Central des Ponts et Chaussees, Paris, pp. 243-252
  • Mahutka K.P. und Grabe J. (2006): Zur Abschätzung von Erschütterung und Sackungen in der Umgebung von Rammarbeiten. VDI-Fachtagung Baudynamik, Kassel, VDI-Berichte Nr. 1941, VDI-Verlag GmbH, Düsseldorf, 71-84
  • Mahutka K.-P., König F. und Grabe J. (2006): Numerical modeling of pile jacking, driving and vibro driving. Proceedings of International Conference on Numerical Simulation of Construction Processes in Geotechnical Engineering for Urban Enviroment (NSC06), Bochum, ed. by T. Triantafyllidis, Balkema, Rotterdam, pp. 235-246
  • Grabe J. and Mahutka K.-P. (2005): Long-term evenness of pavements with respect to soil deformations. Published in electronic proceedings of 7th International Conference on the Bearing Capacity of Roads, Railways and Airfields 2005, Trondheim (BCRA '05)
  • Grabe J. und Mahutka K.-P. (2005): Finite-Elemente-Analyse zur Vibrationsrammung von Pfählen. Bautechnik, 82(9):632-640
  • Mahutka K.-P. und Grabe J. (2005): Numerical investigations of soil compaction and vibration propagations due to strong dynamic excitation. Electronic Proceedings of Joint ASCE/ACME/SES Conference on Mechanics of Materials - McMat 2005, Baton Rouge (USA)
  • Mahutka K.-P. und Grabe J. (2005): Erschütterungs- und Sackungsprognose im Nahfeld von Rammarbeiten. Tagungsband zum Pfahlsymposium 2005 an der TU Braunschweig, Mitteilungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 80, 97-113
  • Mahutka K.-P. (2004): Anwendung der FEM zur Simulation der Verdichtung rolliger Böden. Tagungsband zur Baugrundtagung 2004 in Leipzig - Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', 16-16, Deutsche Gesellschaft für Geotechnik (DGGT)
  • Grabe J., Kelm M. und Mahutka K.-P. (2003): Zur Modellierung der Verdichtung rolliger Böden. Veröffentlichungen des Arbeitsbereiches Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 5, 83-107

Link to list of ongoing research projects
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Set-up of displacement piles

Status: 06.12.2024
Link to list of ongoing and completed research projects

General data

  • Funding: Hamburg University of Technology (2005-2007), Deutsche Forschungsgemeinschaft (DFG), project GR 1024/2-1 und 2-3
  • Duration: 2003-2005 (TUHH), 2005-2007 (DFG), 2007-2009 (DFG)
  • Researcher: Florian König (2003-2007), and Philipp Busch (2007-2009)
  • Status: Completed project, interim and final report, PhD thesis published in institute's series (Vol. 17)

Project description

The external load-bearing capacity of displacement piles is generally obtained from empirical values or from static or dynamic test loads shortly after pile production. The load-bearing capacity determined here is assigned to the pile as a constant value over time. This does not take into account the fact that the load-bearing capacity of a pile can change over a period of several weeks to several years after production. An increase in load-bearing capacity is often observed over time, which is mainly referred to as accretion. Consideration of this effect is of interest for newly constructed piles, where the load-bearing capacity can increase considerably after construction over the further course of construction until full utilization. Furthermore, the aspect of increasing the bearing load is of importance for old pile foundations that are to experience an increase in load due to a change in utilization, extension, or reuse of the supporting structure.

By analysing pile test loads after different service lives and our own long-term field tests with pressure probes, the effect of the increase in bearing load was first empirically proven. The characteristics and magnitude of the effect were identified as a function of the decisive frame parameters. In a further step, the causes of the increase were investigated using laboratory tests and numerical simulations of pile production in order to finally obtain a model for the decisive mechanisms and the basis for a prediction of the effect.

Project relevant publications

  • Busch P. (2010): Forschungsprojekt zum zeitabhängigen Tragverhalten von Verdrängungspfählen. In: Tagungsband zur 31. Baugrundtagung 2010 in München, S. 187-191
  • König F. (2008): Zur zeitlichen Traglastentwicklung von Pfählen und der nachträglichen Erweiterung bestehender Pfahlgründungen. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 17
  • Grabe J., König F. und Putzier D. (2008): Wiederverwendung von vorhandenen Gründungen am Beispiel der Elbphilharmonie und die juristische Lösung der damit verbundenen Risiken. In: Jahrbuch Baurecht 2008, Werner Verlag, S. 189-223
  • König F. (2007): Anwachsphänomene bei Pfählen am Beispiel der Elbphilharmonie. In: Tagungsband der 74. Tagung der norddeutschen Geologen 2007 in Hamburg, S. 61-62
  • König F. and Grabe J. (2006): Time-dependent increase of the bearing capacity of displacement piles. In: Proceedings of 10th International Conference on Piling and Deep Foundations 2006 in Amsterdam, pp. 709-717
  • König F., Grabe J., Franke J. and Woldt J. (2006): Load bearing behaviour of an existing pile foundation and its changes with time. In: Proceedings of International Conference on Reuse of Foundations for Urban Sites, Watford, UK, pp. 199-21
  • König F. (2006): Je älter, desto besser - Pfahlgründungen werden mit der Zeit stabiler. In: TUHH Spektrum, Ausgabe Mai 2006, S. 10-11
  • Grabe J. und König F. (2006): Zeitabhängige Traglaststeigerung von Verdrängungspfählen. In: Tagungsband zur 29. Baugrundtagung in Bremen 2006, S. 291-298, Hrsg. Deutsche Gesellschaft für Geotechnik e.V., Deutscher Verkehrs-Verlag, Hamburg

  • Grabe J. und König F. (2006): Zeitabhängige Traglaststeigerung von Pfählen am Beispiel der Elbphilharmonie. In: Bautechnik, 83(3):167-175

Link to list of ongoing and completed research projects

Optimization of geotechnical constructions and construction methods

Status: 06.12.2024
Link to list of ongoing research projects
Link to list of completed research projects

General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2005 to 2009 (48 months)
  • Researcher: Steffen Kinzler
  • Status: Completed project, PhD thesis is published in institute's series (Vol. 23)

Project description

The difficulty in the design and construction of geotechnical structures lies in the diverse failure mechanisms and their interconnections. In addition, many factors influencing the calculation depend on the selected design. Achieving a utilization factor of almost 100 % for all components is only possible in individual cases. The optimization of design, safety level, dimensioning, construction process and construction costs is in the interest of all parties involved and forms the basis of a promising market position in construction practice. As part of the project, an interdisciplinary approach to optimization was developed and effective solutions were found using modern methods based on multi-criteria numerical optimization. In particular, target-oriented adaptive methods were tested with regard to their mode of action and specially adapted to geotechnical issues.

Project relevant publications

  • Kinzler S. (2011): Zur Parameteridentifikation, Entwurfs- und Strukturoptimierung in der Geotechnik mittels numerischer Verfahren. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 23
  • Grabe J., Kinzler S., Pucker T. und Mardfeldt B. (2010): Untersuchung des Tragverhaltens und der Anwendbarkeit numerischer Optimierungsverfahren für Kaikonstruktionen. In: Tagungsband der 31. Baugrundtagung 2010 in München, S. 123-129
  • Grabe J. and Kinzler S. (2010): Application of numerical optimization in geotechnics. In:  Proceedings of 4th International Conference on Structural Engineering, Mechanics and Computation in Cape Town (South Africa), short version pp. 288, long version electronically published, CRC Press
  • Kinzler S. and Grabe J. (2009): Numerical optimization of geotechnical construction. In: Proceedings of International Conference on Soil Mechanics and Foundation Engineering (ICSMFE)
  • Kinzler S. und Grabe J. (2009): Application of multi-criteria numerical optimization in geotechnical engineering. In: Proceedings of 18th Int. Conf. on the Application of Computer Science and Mathematics in Architecture and Civil Engineering, Weimar (Germany)
  • Kinzler S. und Grabe J. (2009): Entwurf geotechnischer Konstruktionen unter Anwendung der multikriteriellen Optimierungt. In: Tagungsband zum 3. Workshop des Arbeitskreises AK1 1.6 der DGGT an der BAW Karlsruhe zum Thema "Aktuelle Entwicklungen bei der Anwendung numerischer Verfahren in der Geotechnik", S. 31-46
  • Kinzler S., König F. und Grabe J. (2007): Entwurf einer Pfahlgründung unter Anwendung der Mehrkriterien-Optimierung. In: Bauingenieur, 82(9):367-379
  • Kinzler S. und Grabe J. (2006): Wirtschaftliche Optimierung rückverankerter Spundwandkonstruktionen. In: Tagungsband zum Workshop Optiminierung in der Geotechnik - Strategien und Fallbeispiele in Hamburg 2006, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 12, S. 61-86

Link to list of ongoing research projects
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Tertiary compression of organic marine sediments

Status: 06.12.2024
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Link to list of completed research projects

General data

  • Funding: Hamburg University of Technology (2005-2009), Free Hanseatic City of Hamburg, postdoc scholarship (2011-2012)
  • Duration: 2005-2009, 2011-2012
  • Researcher: Olaf Möller (2005-2009), Ph.D Marta Boso (2011-2012)
  • Status: Completed project, PhD thesis is published in institute's series (Vol. 21)

Project description

Long-term creep tests in the oedometer had shown that marine organic sediments exhibit creep behaviour that deviates from the norm: The rate of creep strain did not decrease monotonically as usual, but a temporary increase in the creep rate occurred repeatedly. This phenomenon is referred to in the literature as ‘tertiary compression’. As part of the research project, various hypotheses on the physical causes (mechanical and thermal), chemical and biological causes of tertiary compression were investigated experimentally using creep tests.

Project relevant publications

  • Boso M. and Grabe J. (2012): Long term compression behaviour of soft organic sediments.In: Proceeding of ISSMGE TC-101 Workshop on Multiphysical Testing of Soils and Shales 2012 in Lausanne/Switzerland, Springer Series in Geomechanics and Geoengineering, pp. 249-254
  • Möller O. (2010): Zum Langzeit-Kompressionsverhalten weicher organischer Sedimente. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik, Heft 21
  • Möller O. (2007): Kriechen von marinen Böden. In: Tagungsband der 74. Tagung der norddeutschen Geologen 2007 in Hamburg, S. 56
  • Möller O. (2008): Langzeit-Ödometerversuche an weichen organischen Böden. In:  Tagungsband zur Spezialsitzung "Forum für junge Geotechniker" der 30. Baugrundtagung in Dortmund, S. 16-19, Deutsche Gesellschaft für Geotechnik

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Installation influence from pile driving in quay wall construction

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 1096/1 “Ports for container ships of future generations”, cohort 1
  • Duration: 2005 to 2008 (36 months)
  • Researcher: Sascha Henke
  • Status: Completed project

Project description

The production of piles plays a particularly important role in the construction of quays. The quay is usually founded on a girder grid. Such girder grids are characterized by the fact that they contain numerous intersecting piles. These piles not only influence each other in terms of their load-bearing behaviour, but the piles also influence each other during production, which can, for example, lead to additional deformation of the piles as a result of production. Although pile foundations have been a popular foundation option for a long time, it is still not possible to predict these additional stresses.

As part of the research training group, numerical analyses using the Finite Element Method (FEM) and comparative measurements on real structures were used to investigate the extent of the mutual influence of the soldier piles due to the manufacturing process. For example, spatial FEM simulations were used to calculate the additional deformation that an inclined pile undergoes as a result of driving an intersecting pile.

In order to be able to carry out such calculations, it must be possible to numerically simulate the production of piles in the three-dimensional continuum. This enables a further aspect of research, as such models can also be used to analyse the production-related changes in soil properties in the near field of a pile due to the production process. This project therefore also investigated how the near-field around the pile to be manufactured changes when different manufacturing processes (pressing, impact driving, vibratory driving) are used.

 

Figure: Axisymmetric FEM model to simulate vibratory pile driving into the subsoil

Project relevant publications

  • Henke S. (2008): Herstellungeinflüsse aus Pfahlrammung im Kaimauerbau. Dissertation. Technische Universität Hamburg-Harburg (TUHH),  Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 18
  • Henke S. (2008): Numerical Simulation of Pile Penetration Processes Using Abaqus. Presentation on  Abaqus Homepage 
  • Henke S. und Grabe J. (2008): Numerische Untersuchungen zur Propfenbildung in offenen Profilen in Abhängigkeit des Einbringverfahrens. In: Bautechnik, 85(8):521-529
  • Henke S. and Grabe J. (2008): Numerical Investigation of the Interaction Between Inclined Piles and Newly Driven Piles in Pile Grallages. Proc. of 11th Baltic Sea Geotechnical Conference in Gdansk, pp. 707-714, ed. by Z. Mlynarek, Z. Sikora and E. Dembicki, Polish Committee on Geotechnics & Gdansk University of Technology
  • Henke S. and Grabe J. (2008): Numerical Investigation of Soil Plugging Inside Open-ended Piles With Respect to the Installation Method. Acta Geotechnica, 3(3):215-223
  • Hügel H.M., Henke S. and Kinzler S. (2008): High Performance Abaqus Simulations in Soil Mechanics. Proc. of Abaqus Users Conference 2008 in Rhode Island (USA), pp. 192-205
  • Henke S. (2008): Numerische und messtechnische Untersuchungen zur Pfahlrammung. Tagungsband zum Workshop Seehäfen für Containerschiffe zukünftiger Generationen in Hamburh 2008, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 16, S. 133-172
  • Henke S. und Grabe J. (2007): Simulation of Pile Installation by Three-Dimensional Finite Element Analysis. Proceedings of 14th Darmstadt Geotechnical Conference 2007, Series Darmstadt Geotechnics, No. 15, pp. 179-192
  • Henke S., Grabe J. und Schümann B. (2007): Berücksichtigung herstellungsbedingter Einflüsse. Tagungsband Bemessung mit Finite-Elemente-Methoden, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 14, S. 107-132
  • Henke S. und Grabe J. (2007): Messtechnische Untersuchungen zur Pfahlherstellung während der Rammarbeiten am Container-Terminal CT4 Bremerhaven. Tagungsband zum HTG-Kongress 2007 in Dresden, Hrsg. Hafenbautechnische Gesellschaft, S. 221-231
  • Henke S. und Hügel H.M. (2007): Räumliche Analysen zur quasi-statischen und dynamischen Penetration von Bauteilen in den Untergrund. Tagungsband zur 19. deutschsprachigen Abaqus-Benutzerkonferenz 2007 in Baden-Baden, Abschnitt 2.13
  • Grabe J., Henke S. und Schümann B. (2007): Numerische Simulation von Rammarbeiten im Erdwiderstandsbereich von Baugrubenwänden. Bautechnik, 84(8):519-524
  • Henke S. und Grabe J. (2007): Simulation der Pfahleindringung mittels dreidimensionaler Finite-Elemente Analysen. Vorträge zum 14. Darmstädter Geotechnik-Kolloquium, Mitteilungen des Instituts und der Versuchsanstalt für Geotechnik der Technischen Universität Darmstadt, Heft 76, S. 155-166
  • Henke S., Mahutka K.-P. und Hügel H.M. (2006): Simulation der Pfahleindringung in den Boden. HLRN Nachrichten Nr. 2, S. 3-4
  • Henke S. and Grabe J. (2006): Simulation of pile driving by 3-dimensional Finite-Element analysis. Proceedings od 17th European Young Geotechnical Engineers' Conference, Zagreb, Crotia, ed. by V. Szavits-Nossan, CroatianGeotechnical Society, pp. 215-233

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Deformation of monopiles under cyclic loading

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2005 to 2007
  • Researcher: Jan Dührkop
  • Status: Completed project, PhD thesis published in institute's series (Vol. 20)

Project description

The deformation behaviour of monopiles in the cohesionless seabed under cyclic loading was investigated based on physical modelling. For this purpose, 1g model tests in a specially designed and built model test rig were performed. The model test rig contains a biaxial loading device, i.e. the load can be applied in two horizontal directions independently of each other. 

Project relevant publication

  • Dührkop J. (2009): Zum Einfluss von Aufweitungen und zyklischen Lasten auf das Verformungsverhalten lateral beanspruchter Pfähle in Sand. PhD thesis. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 20

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Influence of wings on piles with predominantly horizontal loading

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/6-1 und 6-2
  • Duration: 2006 bis 2009 (36 months)
  • Researcher: Jan Dührkop
  • Status: Completed project, PhD thesis published in institute's series (Vol. 20)

Project description

Piles are primarily used in foundation engineering to transfer vertical loads. The horizontal loads and moment loads are comparatively low. The horizontal pile-soil interaction is described approximately by the subgrade reaction modulus method. The subgrade reaction modulus used in the calculation is derived from the modulus of rigidity for simplification purposes. Piles for noise barriers, wind turbines and dolphins, on the other hand, are predominantly loaded horizontally. As these foundation systems are usually statically determinate, the correct recording of the pile-soil interaction in the service and limit state is of essential importance. The load-bearing behaviour can be improved by widening the pile at the pile head. This widening of the cross-section increases the bearing force that can be absorbed. As a result, the pile length can be reduced or the load-bearing capacity increased. Model tests were able to confirm the functionality with an increase in load-bearing capacity of around 30 %. The aim of the research project was to better understand the load-bearing behaviour of predominantly horizontally loaded piles without and with expansion in order to derive more accurate design methods. The methods used are primarily model tests, a large-scale test and computer simulations based on the Finite Element Method (FEM).

Project relevant publications

  • Dührkop J. (2010): Zum Einfluss von Aufweitungen und zyklischen Lasten auf das Verformungsverhalten lateral beanspruchter Pfähle in Sand. Dissertation. Technische Universität Hamburg-Harburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 20
  • Dührkop J., Grabe J., Bienen B., White D.J. and Randolph M. (2010): Centrifuge experiments on laterally loaded piles with wings. In: Proceedings of International Conference on Physical Modelling in Geotechnics (ICPMG) in Zürich/Switzerland, Vol. 2, pp. 919-924, CRC Pressührkop J. und Grabe J. (2009): Zum Tragverhalten von horizontal belasteten Flügelpfählen. In: Bautechnik, 86(12):756-764
  • Grabe J. und J. Dührkop (2009): DFG-Abschlussbericht. Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Dührkop J. und Grabe J. (2009): Zum Tragverhalten von horizontal belasteten Flügelpfählen. In: Bautechnik, 86(12):756-764
  • Dührkop J. and Grabe J. (2009): Design of Laterally Loaded Piles with Bulge. In: Proc. of International Conference on Ocean, Offshore and Artic Engineering (OMAE) in Honolulu (USA), ASCE, electronically published under No. OMAE2009-79087
  • Grabe J. und J. Dührkop (2008): DFG-Zwischenbericht und Fortsetzungsantrag. Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Dührkop J. und Grabe J. (2008): Laterally Loaded Piles With Bulge. In: Journal of Offshore Mechanics and Artic Engineering, electronically published under Link, DOI: 10.1115/1.2904589
  • Grabe J. und Dührkop J. (2008): Zum Tragverhalten von überwiegend horizontal belasteten Pfählen. In: Tagungsband zur 30. Baugrundtagung in Dortmund, S. 143-150, Deutsche Gesellschaft für Geotechnik
  • Dührkop J. and Grabe J. (2008): Improving the Lateral Bearing Capacity of Monopiles by Welded Wings. In: Proceedings of 2nd British Geotechn. Ass. Int. Conf. on Foundations ICOF 2008 in Dundee (UK), pp. 849-860, IHS BRE Press
  • Grabe J. und Dührkop J. (2007): Laterally loaded piles with bulge. In: Proceedings of 26th International Conference on Offshore Mechanics and Artic Engineering 2007 in San Diego, USA, ASME (available on CD-ROM, No. OMAE2007-29046)
  • Grabe J., Dührkop J., Henke S., Kinzler S. und König F. (2007): Pfähle mit veränderlichem Querschnitt - konische Pfähle, Fertigteilpfähle mit Fußaufweitung und Flügelpfähle. In: Tagungsband zum Pfahl-Symposium 2007, Mitteilungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 84, S. 131-155

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Traffic-caused vibration of subsoil - sub-project dispersion wave measurement

Status: 06.12.2024
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General data

  • Funding: Deutsches Elektronen-Sychrotron (DESY)
  • Duration: 2006 bis 2007 (12 months)
  • Researcher: Stephan Wendt
  • Status: Completed project, final report

Project description

The propagation speed of surface waves depends on the frequency, as the penetration depth increases with the wavelength and the ground is stiffer depending on the stress and therefore the depth, meaning that the speed increases with a longer wavelength. This phenomenon is utilized in so-called dispersion wave measurements. A harmonic (stationary) concentrated wave field of constant frequency f is generated at the surface of the subsoil using a vertically oscillating exciter (shaker). The amplitude and phase of the surface vibration are measured along a radius using vibration transducers (geophones). The phase position is obtained by comparing the vibrations recorded at the respective measuring point. From this, the length of the Rayleigh wave λ and the corresponding wave velocity can be determined using c = fλ. The aim of the project was to develop a method for the inverse identification of soil parameters from dispersion wave measurements and a derived estimate of the bearing density.

 

Figure: Use of the shaker for dispersion wave measurements in the field

Project relevant publications

  • Grabe J., Henke  S., Kinzler S. and Pucker T. (2010): Inverse determination of soil density and stress state using dispersion wave measurements and cone penetration tests in a non-layered soil. In: Soil Dynamics and Earthquake Engineering, 30(6):481-489
  • Grabe J. and Vrettos C. (1989): Dispersion measurements to estimate compaction effect on granular soils. In: Proceedings of 4th International Conference on Soil Dynamics and Earthquake Engineering, Mexico City

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Numerical simulation of unsaturated soils based on a mixture theory

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2008 to 2011 (48 months)
  • Researcher: Björn Schühmann
  • Status: Completed project, PhD thesis published in institute's series (Vol. 35)

Project description

The stress-strain and permeability behaviour of the unsaturated soil is characterized by capillary effects. The project focussed on the numerical simulation of the unsaturated soil based on mixture theory including a dynamic three-phase model. As part of the project, a user element (UEL) for the dynamic three-phase model was developed for the Abaqus/Standard software based on the work of Öttl (2003) and Holler (2006). The user element has displacement, pore water pressure and pore air pressure degrees of freedom and is based on the u-p-p formulation of the field equations of mixture theory. The user routine contains the kinematic equations, balance equations and constitutive equations, so that Abaqus/Standard only has to assemble the element matrices and element load vectors and solve the system of equations.

Project-relevant publications

  • Schümann B. (2010): Dynamisches Dreiphasenmodell auf Basis der FEM. In: Tagungsband der 31. Baugrundtagung 2010 in München, S. 45-52
  • Schümann B. (2010): Modeling of soils as multi-phase materials with Abaqus. In: Proceedings of SIMULIA Customer Conference 2010 at Providence/USA, pp. 384-399
  • Schümann B. (2015): Beitrag zum dynamischen Dreiphasenmodell für Boden auf Basis der Finite-Elemente-Methode. Dissertation. Technische Universität Hamburg-Harburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 35

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Numerical simulation of geotechnical processes with large soil deformation by means of FEM with the Coupled Eulerian-Lagrangian (CEL) approach

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 1096/2 “Ports for container ships of future generations”, 2nd cohort
  • Duration: 2009 to 2011 (36 months)
  • Researcher: Gang Qiu
  • Status: Completed project, PhD thesis published in institute's series (Vol. 24)

Project description

In extreme load situations, such as the failure of a quay due to bollard pull in combination with extreme water levels, axial failure of the inclined pile, ploughing of the piles through the ground or grounding of ships, large deformations are caused in the ground and in the structure. The same applies to the installation of profiles into the subsoil. The Finite Element Method (FEM) with Lagrangian description of the kinematic variables is not or only partially suitable for numerical modelling of such processes. As part of the project, the FEM based on the Coupled Eulerian-Lagrangian (CEL) approach was primarily used to solve initial boundary value problems with large soil deformations. 

Project-relevant publications

  • Gang Q. (2012): Coupled Eulerian Lagrangian Simulations of Selected Soil-Structure Problems. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 24

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Finite Element-based multicriteria numerical optimization of geotechnical structures in the servicability state (FEMNOG)

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/9-1 und 9-3
  • Duration: 2009-2011 (9-1) und 2013-2015 (9-3)
  • Researcher: Tim Pucker (9-1), and Karlotta Seitz (9-3)
  • Status: Completed project, final report, PhD theses by Tim Pucker, and Karlotta Seitz published in institute's series (Vol. 28 and 45)

Project description

The design of geotechnical load-bearing systems is an extremely complex process, as a large number of criteria have to be taken into account, including load-bearing capacity in the limit and service condition, technical feasibility and cost aspects. The geotechnical design has therefore been largely based on experience and the study of variants. As part of the project, multi-criteria optimisation methods were combined with the Finite Element Method (FEM) in order to take into account the deformation behaviour of geotechnical load-bearing systems in design optimisation. Furthermore, the possible applications of automated design optimisation in geotechnical engineering were examined.

Project-relevant publications

  • Seitz K. (2020): Zur Topologieoptimierung von geotechnischen Strukturen und zur Tragfähigkeitssteigerung des Baugrunds durch Scherfugenverfestigung. Dissertation. Technische Universität Hamburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 45
  • Grabe J. und K. Seitz (2015): DFG-Abschlussbericht. Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Pucker T. (2013): Stoffmodell zur Modellierung von stetigen Materialübergängen im Rahmen der Optimierung geotechnischer Strukturen. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 28
  • Pucker T. (2012): Zur Topologieoptimierung in der Geotechnik. In: Tagungsband zur 32. Baugrundtagung 2012 in Mainz, Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', S. 67-73
  • Grabe J., Pucker T. and Busch P. (2012): Non-linear numerical model for the design process of deep foundations with regard to effects of pile installation. In:  Proceedings of 9th International Conference on Testing and Design Methods for Deep Foundations 2012 in Kanazawa/Japan,edited by T. Matsumoto, pp. 55-64, Kanazawa e-Publishing
  • Grabe J. und T. Pucker: DFG-Zwischenbericht und Fortsetzungsantrag. Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Grabe J. und Pucker T. (2011): Beitrag zum Entwurf und zur Ausführung von kombinierten Pfahl-Plattengründungen. In: Bautechnik 88(12):828-835
  • Pucker T. and Grabe J. (2011): Structural optimization in geotechnical engineering - basics and application. In: Acta Geotechnica 6:41-49, DOI: 10.1007/s11440-011-0134-7
  • Grabe J., Pucker T. und Busch P. (2011): Optimierung einer Kombinierten Pfahl-Plattengründung mit einem nichtlinearen Berechnungsmodell mit Berücksichtigung von Pfahlherstellungseinflüssen. In: Tagungsbeiträge zur 8. Österreichischen Geotechniktagung in Wien, Österreichischer Ingenieur- und Architekten-Verein, S. 171-183
  • Grabe J., Kinzler S., Pucker T. und Mardfeldt B. (2010): Untersuchung des Tragverhaltens und der Anwendbarkeit numerischer Optimierungsverfahren für Kaikonstruktionen. In: Tagungsband der 31. Baugrundtagung 2010 in München, S. 123-129
  • Pucker T. und Grabe J. (2010): Traglasterhöhung von Fundamenten durch gezielte Bodenverbesserung. In: Baugrundverbesserung in der Geotechnik, Tagungsband zum Symposium Baugrundverbesserung in der Geotechnik, Dietmar Adam und Richard Herrmann (Hrsg.), Institut für Geotechnik der Universität Siegen, S. 261-275

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Geotheral and sorption-based air-conditioning (GSGK)

Status: 06.12.2024
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General data

  • Funding: Bundesministerium für Wirtschaft und Energie (BMWi), joint project with Institute for Thermofluiddynamics at TUHH (Prof. Gerhard Schmitz)
  • Duration: 2009 to 2011 (36 months)
  • Researcher: Xiaolong Ma
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 25)

Project description

Sorption-based air conditioning is a further development of evaporative cooling. In contrast to conventional air conditioning, the task of dehumidification is separated from cooling. For this purpose, the humid air is dried using a hygroscopic agent. The water vapour from the air is deposited on the surface of the sorbent (adsorption) or dissolved in it (absorption). Pre-drying means that the air does not have to be cooled below the dew point. Therefore, a heat sink with a higher temperature level, such as the ground, can be used directly. The idea of geothermal and sorption-supported air conditioning (GSGK) combines sorption technology and near-surface geothermal energy.

As part of the joint project, a pilot plant was planned, built and installed in HafenCity Hamburg and operated for a period of two years, see Figure below. The geothermal plant consisted of three borehole heat exchangers with a length of 75 metres and five energy piles with a length of 14 metres. During operation, the plant was run under various conditions. As part of our institute's sub-project, numerical analyses of the heat transport in the subsoil and the heat extraction capacity for the borehole heat exchangers and the energy piles were also carried out on the basis of the Finite Element Method (FEM).

 

Figure: Photo of the geothermal plant in HafenCity Hamburg

Project-relevant publications

  • Ma X. (2013): Nutzung der oberflächennahen Geothermie mittels Energiepfählen und Erdwärmesonden. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 25
  • Ma X. und J. Grabe (2011): Ökologische Klimatisierung: Pilotanlage zur geothermisch- und sorptionsgestützten Klimatisierung in der HafenCity Hamburg. In: Tagungsunterlagen zum Geothermie-Kongress 2011 in Bochum, veröffentlicht auf CD-ROM
  • Ma X., Qiu G. und J. Grabe (2011): Zur thermisch-hydraulisch-mechanisch gekoppelten Simulation eines Energiepfahls. In: Geotechnik 34(4):264–275, DOI: 10.1002/gete.201100008
  • Ma X. und J. Grabe (2011): Steigerung der Effizienz von Erdwärmesonden durch Luftinjektion ohne Grundwasserströmung. In: Geotechnik 34(1):42–50
  • Wrobel J., Ma X., Schmitz G. und J. Grabe (2010): A dessicant assisted air conditioning system with use of geothermal energy. In: Proceedings of World Geothermal Congress 2010 at Bali/Indonesia, paper No. 2934, electronically published
  • Ma X. and J. Grabe (2010): Efficiency increase of soil heat exchangers due to groundwater flow and air injection wells. In: Proceedings of World Geothermal Congress 2010 at Bali/Indonesia, paper No. 3221, electronically published
  • Ma X. and J. Grabe (2010): Field test of a geothermal system in HafenCity Hamburg. In: Proceedings of GEOSHANGHAI 2010, ASCE, Geotechnical Special Publication No. 204 – Geoenvironmental and Geotechnics, pp. 159–166
  • Ma X. und J. Grabe (2010): Kombination von Grundwasser-Zirkulations-Verfahren und Erdwärmeanlagen. In: Vorträge zum 17. Darmstädter Geotechnik-Kolloquium, Mitteilungen des Instituts für Geotechnik der TU Darmstadt, Heft 86, S. 13–25
  • Ma X. und J. Wrobel (2009): Pilotanlage geothermisch- und sorptionsgestützte Klimatisierung in der HafenCity Hamburg. In: Geotechnik 86(11):A9–A11, Technischer Bericht
  • Ma X. und J. Grabe (2009): Modeling of usage of air injection well in a geothermal system. In: Proceedings of COMSOL Conference 2009 at Milano/Italy, electonically published on CD-ROM
  • Ma X. und J. Grabe (2007): Nutzung der oberflächennahen Geothermie in der HafenCity. In: Tagungsband zur 74. Tagung der norddeutschen Geologen 2007 in Hamburg, S. 59-60

Patent

  • Combination of groundwater circulation method and geothermal systems, German patent “Erdwärmeanlage” DE 10 2008 008 762.7, European patent 09401001.4-2301

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Development of an efficient design basis for king piles of combined steel sheet pile walls

Status: 06.12.2024
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General data

  • Funding: Forschungsvereinigung Stahlanwendung e.V. (FOSTA), funding code FOSTA P 813
  • Project management: Arbeitsgemeinschaft industrieller Forschungsvereinigungen "Otto von Guericke" e. V. (AiF), project No. AiF IGF 16493N
  • Project partner: Prof. Dr.-Ing. Ulrike Kuhlmann (Institut für Konstruktion und Entwurf der Universität Stuttgart)
  • Duration: 2010 to 2012
  • Researcher: Christoph Schallück
  • Status: Completed project, final report

Project description

The continuing high growth rates in container shipping are leading to ever larger ship dimensions. A greater draught of the ships requires larger jumps in the quay structures, wider ships require larger container bridges. The resulting loads require a much better understanding of the load-bearing behaviour of a quay structure. The following questions were addressed as part of this research project:

  • The larger terrain jumps cause greater buckling lengths of the sheet piling constructions. Larger crane systems cause increased loads on the quay edges. According to EC 3, lateral-torsional buckling analyses must always be performed. The aim is to improve the existing design rules by allowing the supporting effect of the surrounding soil to be applied as a stabilizing element by means of a rotational bedding and the support provided by the intermediate piles on the resistance side.
  • The intermediate piles of a combined sheet pile wall are subjected to earth and water pressure. They transfer these loads to the load-bearing piles. Up to now, the design has been based on empirical values. The aim is to use tests and numerical calculations to determine the exact u stress and load-bearing capacity of the intermediate piles.
  • The various regulations—namely the EAU, the EAB, DIN 1054 and the regulations of the HPA—sometimes describe very different calculation approaches for the verification against wall sinking. The aim is to develop simple and standardized design concepts based on theoretical considerations and numerical calculations.

Figure: Field test to determine the rotational bedding of a king sheet pile

Project-relevant publications

  • Kuhlmann U., Grabe J., Froschmeier B. und C. Schallück (2012): AiF-Abschlussbericht. Institut für Konstruktion und Entwurf der Universität Stuttgart und Institut für Geotechnik und Baubetrieb der Technischen Universität Hamburg-Harburg (TUHH)
  • Kuhlmann U., Grabe J., Froschmeier B. und Schallück C. (2012): Untersuchungen von Tragbohlen kombinierter Stahlspundwände unter Stabilitätsbeanspruchung. Veröffentlichung des Stahl-Informations-Zentrums Düsseldorf "Stahlspundwände (10) – Planung und Anwendung", S. 1–10
  • Schallück C. and Grabe J. (2011): Rotational bedding of open-ended steel profiles in soil. In: Tagungsband zum Workshop Ports for Container Ships of Future Generations, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 22, S. 329–344
  • Kuhlmann U., Grabe J., Froschmeier B., Pavlovicic L., Schümann B. und Schallück C. (2009): Biegedrillknicken von Hauptträgern. In: Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 19, S. 167–190

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Capillary influence on the mechanical behaviour of non-cohesive soils under dynamically highly loaded logistics areas

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/11-1 and 11-2
  • Duration: 2010 to 2014 (48 months)
  • Researcher: Marius Milatz
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 36)

Project description

The long-term durability of road surfaces is an important aspect in traffic route construction, particularly in the case of heavily used logistics areas such as container handling centres. Such roadways are subjected to many millions of load cycles around the clock during their service life when handling containers. From a soil mechanics point of view, the design of such carriageways involves the problem of comprehensively predicting the accumulation of soil deformations, especially when capillary effects are taken into account. 

As part of the project, the mechanical-hydraulic behaviour of the soil during single and repeated passages of heavy vehicles (van carriers or automated guided vehicles) was investigated experimentally, theoretically and numerically. The experiments comprised field measurements on the roadway of a container handling site in Hamburg, 1g model tests, soil mechanical laboratory tests with a novel single shear device for partially saturated soil samples. The numerical investigations were based on the Finite Element Method (FEM) using a dynamic three-phase model for the unsaturated soil based on a mixture theory.

Project-relevant publications

  • Milatz M. (2015): Untersuchungen zum Einfluss der Kapillarität auf das hydraulisch-mechanische Verhalten von granularen Tragschichten für Verkehrswege. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 36
  • Milatz, M. (2015): An experimental method to study the drying-wetting behaviour of a sand. In: Proc. of 6th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT 2015), Guilin, China. Hrsg. von Z. Chen, C. Wei, D. Sun und X. Xu, S. 211–216
  • Renken L., Oeser M., Milatz M. und J. Grabe (2015): Measurement of hydraulic properties of unsaturated permeable polyurethane bound asphalt materials. In: Proceedings of 6th Asia Pacific Conference on Unsaturated Soils (AP-UNSAT) 2015 in Guilin/China, CRC Press
  • Milatz M. und Grabe J. (2015): Zum Einfluss der Teilsättigung auf den Plattendruckversuch. In: Geotechnik 38(1):28–35
  • Milatz M. und Grabe J. (2015): A new simple shear apparatus and testing method for unsaturated sands. In: Geotechnical Testing Journal 38(1), pp. 9–22
  • Grabe J. und Milatz M. (2014): Kapillareinfluss auf das mechanische Verhalten nichtbindiger Böden unter dynamisch hochbeanspruchten Logistikflächen. DFG-Abschlussbericht, Technische Universtät Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Milatz M. und Grabe J. (2014): Triaxial and simple shear tests on unsaturated sand with negative pore water pressures. Proceedings of 6th International Conference on Unsaturated Soils (UNSAT) in Sydney/Australia, pp. 1631–1637
  • Grabe J. und Milatz M. (2014): The change of matric suction due to heavy vehicle crossing. Proceedings of 6th International Conference on Unsaturated Soils (UNSAT) in Sydney/Australia, pp. 1431–1437
  • Milatz M. (2014): Experimentelle Untersuchung der Kapillarität bei Sand unter monotoner und zyklischer Belastung. Tagungsband zum Ohde-Kolloquium 2014 - Aktuelle Themen der Geotechnik, Mitteilungen des Instituts für Geotechnik der TU Dresden, Heft 19, S. 1–13 
  • Milatz M. (2014): Numerische Modellierung der Belastung aus Schwerlastverkehr in Offshore Basishäfen. Tagungsband zum gleichlautenden Workshop an der TU Hamburg-Harburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 31, Seite 161–176
  • Milatz M. (2013): On the control of low negative water pressures in laboratory tests on unsaturated sand. Proc. of 5th International Young Geotechnical Engineer's Conference (YGEC) 2013 in Paris/France, pp. 55–58
  • Milatz M. und Grabe J. (2012): Der Einfluss bewegter Radlasten auf das dynamische System des Untergrundes. Proc. der 4. VDI-Fachtagung Baudynamik 2012, VDI-Berichte 2160, S. 187–196
  • Milatz M. und Grabe J. (2012): Der Einfluss bewegter Radlasten auf das dynamische System des Untergrundes. In: Tagungsband zur 4. VDI-Fachtagung Baudynamik 2012, VDI-Berichte 2160, S. 187–196

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Fundamental investigations on the drift of piles under cyclic horizontal load with time-varying load direction and on the reduction of pile drift

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/12-1
  • Duration: 2010 to 2011 and 2013-2014 (24 months)
  • Researcher: Christina Rudolph
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 32)

Project description

Piles show an accumulation of deformation with an increasing number of cycles under cyclic horizontal loading with a constant load direction. Preliminary investigations show that piles drift out of the main load direction when subjected to a cyclic horizontal load with a time-varying load direction and exhibit significantly increased deformation rates. This phenomenon is known as pile drift. Variable load directions occur, for example, with wind and wave loads that act on monopile foundations in the offshore sector. As part of the research project, the phenomenon of pile drift under cyclic horizontal load with variable load direction was fundamentally investigated. This includes experimental investigations (1g model tests and ng model tests in a centrifuge, see Figure below) as well as computer simulations based on continuum models (Finite Element Method) and particle models (Discrete Element Method). The objective of the project was to describe and model the phenomenon of pile drift and to develop technical measures to reduce pile drift.

 

Figure: Photo of a centrifuge test at Centre for Offshore Foundation Systems (COFS), University of Western Australia—container filled with sand and installed pile

Project-relevant publications

  • Rudolph C. (2015): Untersuchungen zur Drift von Pfählen unter zyklischer, lateraler Last aus veränderlicher Richtung. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 32
  • Rudolph C. und Grabe J. (2013): Untersuchungen zu zyklisch horizontal belasteten Pfählen bei veränderlicher Lastrichtung. In: Geotechnik 36(2):90–95
  • Rudolph C., Grabe J. and Bienen B. (2013): Deformation behaviour of piles subjected to cyclic lateral loading from a varying direction. In: Proceedings of Conference on Maritime Energy (COME) 2013 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg-Harburg, Heft 26, pp. 147–161
  • Rudolph C. (2012): Modellversuche zur Drift zyklisch horizontal belasteter Pfähle bei veränderlicher Lastrichtung. In: Tagungsband zur 32. Baugrundtagung 2012 in Mainz, Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', S. 119–123

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Load-bearing behaviour of partial displacement bored piles

Status: 06.12.2024
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General data

  • Customer: Bauer Spezialtiefbau GmbH, Schrobenhausen, Germany
  • Duration: 2010
  • Researcher: Philipp Busch
  • Status: Completed project, internal report

Project description

Comparative field tests were carried out on the load-bearing behaviour of partial displacement bored piles at the ‘Hohe Schaar’ site in Hamburg.

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Investigations into the use of METHA material as a building material

Status: 06.12.2024
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General data

  • Customer: Hamburg Port Authority (HPA), Germany
  • Duration: 2009 to 2012 (36 months)
  • Researcher: Kathinka Beyer
  • Status: Completed project, internal report

Project description

On the German North Sea coast and on the lower banks of the Elbe, clay is traditionally used as a cohesive, slightly water-permeable dyke seal. It was assumed that there would be a considerable demand for this type of construction material as part of future adjustments to flood protection systems. As clay is only available as a natural resource to a limited extent, substitutes were tested and utilized where possible. A comparative building material and possible cost- and resource-saving substitute is a product of the METHA sediment treatment plant (mechanical separation and dewatering of harbour sediments). As the pollutant load of dredged material has decreased significantly, particularly in the last 10 years, new possibilities for utilizing METHA material are opening up. Since 2008, for example, METHA material has been used as a LAGA-certified sealing material in landfill construction (LAGA 2008).

There were no assessment criteria for the use of METHA material in dyke construction in 2009. It was necessary to check whether current guidelines and recommendations for the use of clay could also be applied to METHA material. In particular, the recommendations and guidelines of the Hamburg Building Authority, Office for Water Management (1988), recommendations of the Committee for Coastal Defence Works (EAK 2007) and Weißmann (2003) were to be mentioned here. Specifications in the EAK 2002 (2007) with reference to the installation of silt were also not directly transferable, as METHA material typically has different properties to silt due to the manufacturing process.

To investigate the application criteria for the use of dredged material in dyke construction, several test fields were set up in the run-up to the project. For example, a trial field was set up on the Ellerholz Canal in Hamburg using METHA dredged material processed in Hamburg. A test field on the Drewer main dyke, where METHA material was used, was analysed in comparison to the Bostelbeker main dyke and Neß main dyke. In addition, a test field was set up at Maadesiel using dredged material from Bremen and Hamburg.

As part of the research project, further scientific investigations were carried out at TUHH to determine the suitability of METHA material as a dyke construction material. This included the inspection of existing documents, comparative studies on the mechanical-hydraulic behaviour, studies on crack formation and (self-)healing of cracks as well as studies to improve the properties of METHA material. As METHA material typically has a very high water content compared to its shrinkage limit and does not undergo primary shrinkage and other soil-forming processes during production, detailed experimental investigations were carried out to assess the crack resistance of the material as a dyke cover layer. The focus here was on the shrinkage behaviour, the formation, and propagation of cracks and the water balance in dyke cover layers using METHA material.

Project-relevant publications

  • Grabe J. und K. Beyer (2012): Einsatz von METHA-Material als Baustoff. Interner Bericht, Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Beyer K., Grabe J., Kaschel G. and Timmers V. (2012): Development of a large-scale environmental chamber to investigate the dessication behaviour of flood embankment profiles. In: Proceedings of 12th Baltic Sea Geotechnical Conference 2012 in Rostock/Germany, pp. 244–250, electronically published

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Mechanisms of soil plugging in open sections depending on the installation method

Stand: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. HE 5445/1-1
  • Duration: 2010-2012 (24 months)
  • Researcher: Dr.-Ing. Sascha Henke
  • Status: Completed project, final report, habilitation published in institute's series (Vol. 29)

Project description

When open profiles are penetrated into the ground by pressing, impact or vibration ramming, the radial stress in the area of the component base can increase. This phenomenon is known as plug formation. The formation of plugs has an influence on the pile-driving capability and the vertical load-bearing capacity of these open profiles, so it is important to be able to estimate the tendency to form a soil plug in advance of the pile-driving work. There are many profiles that can be prone to plug formation. These include open steel pipes, double T-sections, but sheet piling and box sections can also form a solid soil plug inside them under certain boundary conditions. The formation of a soil plug inside the profile depends, among other things, on the installation method, the soil conditions and the pile geometry. Until now, it has been difficult to predict the tendency to form plugs. Traditionally, many significant influencing variables are not taken into account. In particular, the influence of the installation method can so far only be determined as a result of metrological investigations. For example, Jardine et al. (2005) state that open pipes that are pressed in tend to form plugs if they have a correspondingly small diameter. In contrast, Randolph (2003) predicts that impact-rammed pipes do not tend to plug due to the inertia of the soil body in the pipe. No statements have yet been found for vibration pile driving.

As part of the project, the causes, and effects of the phenomenon of plug formation were fundamentally investigated. This included experimental investigations (1g model tests and ng model tests in a centrifuge), theoretical investigations and numerical investigations based on the Finite Element Method (FEM). The simulation of component penetration as part of the FEM was based on the Coupled Eulerian-Lagrangian (CEL) approach. The main influencing variables were varied as part of the modelling tests. The computer simulations were validated using the results of the model tests, and events that were not covered experimentally were also investigated. The aim was to develop a design basis for taking plug formation into account.

Project-relevant publications

  • Henke S. (2013): Untersuchungen zur Pfropfenbildung infolge der Installation offener Profile in granularen Böden. Habilitation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik, Heft 29
  • Grabe J., Henke S., Pucker T., Hamann T. (2013): CEL Simulations for soil plugging, screwed pile installation and deep vibration compaction. In: Proceedings of International Conference on Installation Effects in Geotechnical Engineering 2013 in Rotterdam/Netherlands, pp. 118-127, Taylor & Francis Group, London
  • Grabe J. and Henke S. (2012): Field measurements regarding the influence of the installation method on soil plugging in tubular piles. In: Acta Geotechnica, DOI: 10.1007/s11440-012-0191-2
  • Henke S. (2012): Zuschrift zur Publikation 'Untersuchungen der Pfropfenbildung an offenen Verdrängungspfählen'. In: Bautechnik 89(10):727-730
  • Fischer J., Henke S. und Höhmann S. (2012): Stress development inside large diameter pipe piles using a soil plug forcing system. In: Proceedings of ASME 2012 31st International Conference on Ocean, Offshore and Artic Engineering (OMAE2012) in Rio de Janeiro/Brazil, electronically published under OMAE2012-83401
  • Henke S. (2012): Large deformation numerical simulations regarding soil plugging behaviour inside open-ended piles. In: Proceedings of ASME 2012 31st International Conference on Ocean, Offshore and Artic Engineering (OMAE2012) in Rio de Janeiro/Brazil, electronically published under OMAE2012-830389
  • Henke S. (2012): Full-scale site investigation on soil-plugging inside tubular piles. In: Proceedings of ASME 2012 31st International Conference on Ocean, Offshore and Artic Engineering (OMAE2012) in Rio de Janeiro/Brazil, electronically published under OMAE2012-83038
  • Henke S. (2012): Vertical bearing capacity of open-ended piles with respect to soil plugging. In: Proceedings of 12th Baltic Sea Geotechnical Conference 2012 in Rostock/Germany, pp. 71-78, electronically published
  • Henke S. (2011): Numerical and experimental investigations of soil plugging in open-ended piles. In: Tagungsband zum Workshop Ports for Container Ships of Future Generations, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 22, S. 97-122
  • Henke S. (2010): The influence of the installation method on soil plugging in open-ended piles. In: Proceedings of 4th International Conference on Structural Engineering, Mechanics and Computation in Cape Town (South Africa), short version pp. 343, long version electronically published, CRC Press
  • Grabe J. and Henke S. (2010): High-performance Finite Element and Coupled Eulerian-Lagrangian simulations of pile installation proceses. In: Proceedings of 4th International Conference on Structural Engineering, Mechanics and Computation in Cape Town (South Africa), short version pp. 63, long version published electronically, CRC Press
  • Henke S. (2009): Simulation der Einbringung offener Profile - Untersuchungen zur Propfenbildung. In: Veröffentlichungen des Instituts für Geotechnik und Bauebtrieb der TU Hamburg, Harburg, Heft 19, S. 57-79

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Stability of underwater excavations pits

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2010 to 2013
  • Researcher: Julian Bubel
  • Status: Completed project

Project description

In order to construct heavyweight foundations for offshore wind turbines, a subgrade must be created on the seabed. Various geotechnical questions arise in this context:

  • What technology should be used to construct the underwater construction pit so that underwater embankments can be constructed that are as steep as possible and thus minimize the impact on the area?
  • How steep can underwater embankments be temporarily and permanently?
  • What is the influence of currents, waves and other disturbances?
  • How long can underwater construction pits be operated, taking into account the load of soil particles on the seabed?

Experimental and numerical investigations were carried out to clarify these questions.

Project-relevant publications

  • Bubel J., Grabe J. (2015): Unterwasserböschungen in kohäsionslosen Böden unter Wellenbeanspruchung. In: Aktuelle Forschung in der Bodenmechanik 2015 – Tagungsband zur 2. Deutschen Bodenmechanik Tagung in Bochum, T. Schanz, A. Hettler (Ed.), Springer, S. 225–241
  • Bubel J., Pick M.-A., Grabe J. (2015): Stability of artificial subaqueous slopes in sandy soils under wave loads. In: Proceedings of 34th International Conference on Ocean, Offshore and Artic Engineering 2015 in St. John's (Canada), electronically published under paper No. OMAE2015-41827
  • Bubel J. und Grabe J. (2014): Unterwasserböschungen in sandigen Böden. In: Binnenschifffahrt 2014(12):48–53
  • Bubel J. and Grabe J. (2013): Wave-induced bottom pressure on submarine slopes. In: Proceedings of Conference on Maritime Energy (COME) 2013 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg-Harburg, Heft 26, pp. 211–227
  • Bubel J. and Grabe J. (2012): Stability of submarine foundations pits. In: Proceedings of 7th International Conference on Offshore Site Investigation and Geotechnics 2012 in London/UK, pp. 347–354, published by Society for Underwater Technology
  • Bubel J. und Grabe J. (2012): Stability of submarine foundation pits under wave loads. In: Proceedings of 31th International Conference on Ocean, Offshore and Artic Engineering (OMAE) in 2012 in Rio de Janeiro/Brazil, electronically published under OMAE2012-83027

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Development of a constitutive model for modelling continuous material transitions in the context of optimising geotechnical structures

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2011 to 2013
  • Researcher: Tim Pucker
  • Status: Completed project, PhD thesis published in institute's series (Vol. 28)

Project description

The numerical multi-criteria optimization of geotechnical structures involves a transition from soil to concrete. In order to be able to simulate this transition gradually, a corresponding material model based on hypoplasticity was developed.

Project-relevant publication

  • Pucker T. (2013): Stoffmodell zur Modellierung von stetigen Materialübergängen im Rahmen der Optimierung geotechnischer Strukturen. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 28

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Investigations as part of the basic task ‘Formation of sealing connections in the stretch of waterways'

Status: 06.12.2024
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General data

  • Funding: Bundesanstalt für Wasserbau (BAW), Karlsruhe, Germany
  • Duration: 2011 to 2013 (24 months)
  • Researcher: Hatice Kaya
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 37)

Project description

Experimental investigations by means of physical modelling (1g model tests) and numerical simulation (FEM) on the formation of sealing connections in the area of waterways, in particular when sheet piling is penetrated by sealing soil layers.

Project-relevant publications

  • Kaya H. (2016): Bodenverschleppung und Spaltbildung infolge der Einbringung von Profilen in Dichtungsschichten aus Ton. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 37
  • Kaya H. und J. Grabe (2015): Numerische Untersuchungen zur Bodenverschleppung und Spaltbildung infolge Spundwandeinbringung in Dichtungsschichten. In: Numerische Methoden in der Geotechnik, Bundesanstalt für Wasserbau (Hrsg.), BAWMitteilungen Nr. 98, S. 47–58
  • Kaya H. und Grabe J. (2015): Untersuchungen zur Spaltbildung bei der Herstellung von Dichtungsanschlüssen im Streckenbereich von Wasserstraßen. In: Vorträge zum 22. Darmstädter Geotechnik-Kolloquium 2015, Mitteilungen des Instituts und der Versuchsanstalt für Geotechnik der Technischen Universität Darmstadt, Heft 94, S. 107–127
  • Kaya H. (2013): Investigation of sheet pile penetration in surface seals by using the Coupled Eulerian-Lagrangian Method. In: Proceedings of 5th International Young Geotechnical Engineer's Conference (YGEC) 2013 in Paris/France, pp. 551–554

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Experimental and numerical investigations of partial displacement piles

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2012-2013
  • Researcher: Philipp Busch
  • Status: Completed project

Project description

Development of a model test rig for the investigation of partial displacement bored piles. Experimental investigations into the influence of the manufacturing parameters on the drilling process for partial displacement bored piles in 1g model tests (pressure chamber). Variation of the drilling tool and the production parameters (feed rate and rotational speed of the screw-type drilling tool).

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Increased efficiency of the geothermal and sorption-based air conditioning system (Eff-GSGK)

Status: 06.12.2024
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General data

  • Funding: Bundesministerium für Wirtschaft und Energie (BMWi)
  • Project management: Projektträger Jülich (PtJ), funding code AZ 03ET1065A
  • Project partner: Institute for Thermofluiddynamics at TUHH (Prof. Dr.-Ing. Gehard Schmitz)
  • Duration: 2012 to 2014 (36 months)
  • Researcher: Frauke Wenzel, Matthias Schuck
  • Status: Completed project, final report

Project description

In the previous project GSGK, the combination of a sorption-supported air conditioning system and a geothermal system was investigated in a pilot plant in HafenCity Hamburg. The objective of this joint project is to further increase the efficiency of geothermal and sorption-based air conditioning. Our institute is pursuing the following goals:

  • Increasing the cold extraction capacity of heat exchangers in the ground (geothermal probes and energy piles) by combining them with an air injection well (creating artificial convective heat transport, especially in locations with low groundwater flow). For this purpose, field tests are carried out on the pilot plant and computer simulations based on the Finite Element Method (FEM).
  • Optimization of the mechanical-hydraulic-thermal behaviour of the backfill material of heat exchanger boreholes. The backfill material must have the highest possible thermal conductivity, low permeability, high ductility under mechanical stress and resistance to fracture during freeze-thaw cycles. For this purpose, laboratory tests were carried out in a new type of triaxial device under real stress and temperature conditions with various backfill materials.
  • Development of design principles for geothermal heat exchangers.

Project-relevant publications

  • Schmitz G., Grabe J. und M. Schuck (2014): Effizientsteugerung der geothermisch- und sorptionsgestützten Klimaanlage. BMWi-Abschlussbericht, Technische Universität Hamburg-Harburg (TUHH), Institut für Thermofluiddynamik
  • Anbergen H., Frank J., Albrecht I., Dittrich H. (2011): Prüfzelle zur Bestimmung des Frost-Tau-Wechsel-Widerstands von Verpressmaterial für EWS. In: bbr Fachzeitschrift für Brunnenbau, 10/2Keine Kopfzellen011, S. 38–43
  • Albrecht I. und Frank J. (2010): Vorversuche an Verpressmaterialien für Erdwärmesonden zum mechanisch-hydraulischen Verhalten bei Frost/Tau-Wechseln. In: bbr Fachzeitschrift für Brunnenbau, 61(5):28–33

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Hydraulic loosening of soils

Status: 06.12.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2011 to 2014
  • Researcher: Bozhana Kocak
  • Status: Completed project, subsequent DFG project GR 1024/20-1

Project description

The focus of the project is the numerical simulation of processes in which a cohesionless soil is eroded with a fluid jet. For the numerical simulation of such physical processes in the soil, which are characterized by very large soil deformations, soil erosion, and sedimentation, a simulation model was developed based on the following theories and methods:

  • Two-phase model for saturated soils based on a mixture theory
  • Implementation of the two-phase model in Smoothed Particle Hydrodynamics (SPH) based on the SHP-codes GADGET and GADGET-H2O → SPH-code GADGET-Soil
  • Implementation of a constitutive model for non-cohesive soils
  • Verification of implementation

Application of the method to simulate a series of physical processes in soil, above all jet grouting in non-cohesive soils.

Project-relevant publications

  • Stefanova B. und Grabe J. (2012): Erste Untersuchungen zur Simulation des Düsenstrahlverfahrens mittels Smoothed Particle Hydrodynamics. In: Tagungsband zum Symposium Baugrundverbesserung in Wien 2012, pp. 133–145
  • Stefanova B., Bubel J. and Grabe J. (2012): Application of SPH to erosion and excavation problems on the examples of jet grouting and offshore engineering. In: Proceedings of 7th International SPHERIC SPH-Workshop 2012 in Prato/Italy, pp. 38–42

Note: The work was continued as part of a DFG project GR 1024/20-1. Further publications on the topic can be found there.

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Novel foundation piles for offshore wind turbines

Status: 06.12.2024
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General data

  • Funding: Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (BMU)
  • Project management: Projektträger Jülich (PtJ), funding code AZ 0325240
  • Research partner: TAGU / Ludwig Freytag, Germany
  • Duration: 2011 to 2013 (24 months)
  • Researcher: Christina Rudolph
  • Status: Completed project, final report, PhD thesis published in institute's series

Project description

The effect of a horizontal load on a vertical foundation element causes a complex reaction of the pile-soil system. The soil can become compacted, loosened, solidified or weakened depending on the magnitude of the load and its initial state. These reactions can also occur simultaneously at different depths. For example, the soil can shear in the pile head area while it solidifies in the pile foot area. The reaction of the pile does not depend on the soil alone, but rather on the overall system, which in turn is influenced by the soil, the pile diameter, the pile bending stiffness, the initial stress state, the load, the load history (cyclicity) and the load speed (dynamics). With regard to the transfer of loads from offshore wind turbines, a deformation criterion is generally imposed on the foundation, which is intended to ensure the serviceability of the wind turbines. In order to comply with this, it is often necessary to choose significantly larger embedment lengths or diameters for monopiles than would be necessary from a purely static point of view.

As part of the project, a new type of wing pile developed at the institute was investigated. It consisted of a conventional steel pipe cross-section that was expanded at the level of the seabed by additional steel plates. This allows the effective lateral bedding of the pile to be significantly increased in this area, which is actually not very load-bearing. This leads to savings in the use of materials. In addition, the driving time is reduced because the required embedment length can be significantly reduced compared to the conventional monopile. The project included experimental investigations (field test on a prototype scale, see Figure below, and soil mechanics laboratory tests with a simple shear device for variable shear stress direction) as well as numerical investigations based on the Finite Element Method (FEM).

 

Figure: Photo of field test at Bremerhaven with two piles and the loading device

Project-relevant publications

  • Rudolph C. (2015): Untersuchungen zur Drift von Pfählen unter zyklischer, lateraler Last bei veränderlicher Richtung. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 32
  • Rudolph C., Bienen B. und J. Grabe (2014): Effect of variation of the loading direction on the displacement accumulation of large-diameter piles under cyclic lateral loading in sand. In: Canadian Geotechnical Journal, 51, S. 1196–1206
  • Rudolph C., Grabe J. und Bienen B. (2014): Drift of piles subjected to cyclic lateral loading from a varying direction: system vs. soil element behaviour. Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Artic Engineering (OMAE) in San Francisco/USA, electronically published under OMAE2014-23212
  • Rudolph C., Grabe J. and Bienen B. (2014): Response of monopiles under cyclic lateral loading with a varying loading direction. In: Proceedings of International Conference on Physical Modelling in Geotechnics (ICPMG) 2014 in Perth/Australia, Vol. 1, pp. 453–458
  • Grabe J. und C. Rudolph (2013): Neuartige Gründungspfähle für Offshore-Windenergieanlagen - Bau und Betrieb eines Testfeldes. BMU-Abschlussbericht, Technische Universität Hamburg-Harburg (TUHH), Institut für Geotechnik und Baubetrieb
  • Rudolph C. und Grabe J. (2013): Untersuchungen zu zyklisch horizontal belasteten Pfählen bei veränderlicher Lastrichtung. Geotechnik, 36(2):90–95
  • Rudolph C. and Grabe J. (2013): Laterally loaded piles with wings - in situ testing with cyclic loading from varying directions. In: Proceedings of 32nd International Conference on Ocean, Offshore and Artic Engineering (OMAE) 2013 in Nantes/France, paper No. OMAE2013-10026
  • Rudolph C., Grabe J. and Bienen B. (2013): Deformation behaviour of piles subjected to cyclic lateral loading from a varying direction. In: Proceedings of Conference on Maritime Energy (COME) 2013 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg-Harburg, Heft 26, pp. 147–161

Link to list of ongoing research projects
Link to list of completed research projects

Dynamic consolidation analysis with direct excplicit time integration based on y two-phase model for saturated soils

Status: 06.12.2024
Link to list of ongoing research projects
Link to list of completed research projects

General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 1096/3 “Ports for container ships of future generations”, 3rd cohort
  • Duration: 2011 to 2013 (36 months)
  • Researcher: Thorben Hamann
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 34)

Project description

Within the framework of the explicit FEM-solver Abaqus/Explicit, a user subroutine of the type VUMAT was implemented that enables dynamic consolidation analyses based on the u-p formulation of the Biot equations. The solution approach is based on the analogy of laminar and acceleration-free transient groundwater flow and transient heat transport due to heat conduction.

Project-relevant publications

  • Heins E., Hamann T., Grabe J. und Hannot S. (2016): Numerical investigation of the influence of the driving frequency during pile installation of tubular piles. In: Geotechnik 39(2):98-109，DOI: 10.1002/gete.201600014
  • Heins E., Grabe J., Hamann T. (2015): Numerische Simulation einer Bodenverbesserungsmaßnahme infolge Rütteldruckverdichtung. In: Numerische Methoden in der Geotechnik, Bundesanstalt für Wasserbau (Hrsg.), BAWMitteilungen Nr. 98, S. 59-68
  • Hamann T. (2015): Zur Modellierung wassergesättigter Böden unter dynamischer Belastung bei großen Bodenverformungen am Beispiel der Pfahleinbringung. Dissertation. Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 34
  • Bubel J. und Hamann T. (2015): Limitations and examples of coupled water-soil FE-analyses. In: Morphodynamics 2015 - Workshop on Numerical Methods of Water-Soil Boundary Layers under Currents and Waves, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 33, S. 37-58
  • Grabe J., Heins E. und Hamann T. (2015): Simulation of ground improvement using deep vibration compaction. In: Proceedings of 6th International Geotechnical Symposium on Disaster Mitigation in Special Geoenvironmental Conditions 2015 in Chennai (India), pp. 281-284
  • Hamann T., Qiu G. und Grabe J. (2014): Application of a Coupled Eulerian-Lagrangian approach on pile installation problems under partially drained conditions. Computers and Geotechnics, 63:279-290
  • Grabe J., Pucker T., Hamann T. und Heins E. (2014): Zur axialen Tragfähigkeit von offenen Profilen in Sand. Tagungsband zur 33. Baugrundtagung 2014 in Berlin, S. 211-218
  • Grabe J., Hamann T. und Chmelnizkij A. (2014): Numerical simulation of wave propagation in fully saturated soil modelled as a two-phase material. Proceedings of 9th International Conference on Structural Dynamics (Eurodyn) 2014 in Porto/Portugal, pp.631-637
  • Grabe J., Pucker T. und Hamann T. (2014): Numerical simulation of pile installation processes in dry and saturated granular soils. In: Proceedings of 8th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE) 2014 in Delft/Netherlands
  • Kreuzer E., Solowjow E., Qiu G., Hamann T. und Grabe J. (2014): Leg-seabed interactions of jack-up vessels due to motions in irregular waves. Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Artic Engineering (OMAE) in San Francisco/USA, electronically published under OMAE2014-24303
  • Grabe J., Busch P. und Hamann T. (2014): On the set-up of piles. Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Artic Engineering (OMAE) in San Francisco/USA, electronically published under OMAE2014-24433
  • Hamann T. (2014): Numerical simulation of pile installation in water saturated soil. Tagungsband zur gleichnamigen Internationalen Konferenz 2014 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 30, S. 171-182
  • Grabe J., Hamann T. and Milatz M. (2013): Numerical simulation of inelastic wave propagation in soil modelled as one- and two-phase medium. Proc. of Vienna Congress on Recent Advances in Earthquake Engineering and Structural Dynamics (VEESD) 2013 in Vienna/Austria, Paper No. 168
  • Hamann T. and Grabe J. (2013): A simple dynamic approach for the numerical modelling of soil as a two-phase material. Geotechnik, 36(3):180-191
  • Hamann T. and Grabe J. (2013): Numerical investigations on vibratory sheet piling in embankments using a multi-phase material. In: Proceedings of 18th International Conference on Soil Mechanics and Geotechnical Engineering 2013 in Paris/France, pp. 719-722
  • Bahr M., Bauer M., Großeholz G., Hamann T. und Leonardi M., Pichler T., Qiu G. und Radisch C. (2013): Seehäfen für Containerschiffe zukünftiger Generationen - Forschungsprojekte der Stipendiaten der dritten Generation. HANSA International Maritime Journal, 150(7):93-97
  • Hamann T., Pichler T. and Grabe J. (2013): Numerical simulation of ship collision with gravity base foundations of offshore wind turbines. In: Proceedings of 32nd International Conference on Ocean, Offshore and Artic Engineering (OMAE) 2013 in Nantes/France, paper No. OMAE2013-11627
  • Qiu G., Hamann T., Grabe J., Hein C. and Howe R. (2013): A case study: construction of bucket foundations for jacpup ships. In: Proceedings of 32nd International Conference on Ocean, Offshore and Artic Engineering (OMAE) 2013 in Nantes/France, paper No. OMAE2013-10009
  • Grabe J., Hamann T. und Qiu G. (2013): Osterbergprobebelastung - Zur Interpretation der Messung von Spitzendruck und Mantelreibung. In: Beiträge zum 28. Christian Veder Kolloquium 2013 in Graz, Veröffentlichungen der Gruppe Geotechnik an der TU Graz, Heft 49, S. 145-162
  • Grabe J., Henke S., Pucker T., Hamann T. (2013): CEL Simulations for soil plugging, screwed pile installation and deep vibration compaction. In: Proceedings of International Conference on Installation Effects in Geotechnical Engineering 2013 in Rotterdam/Netherlands, pp. 118-127, Taylor & Francis Group, London
  • Hamann T. und Grabe J. (2012): Numerical investigations on vibratory sheet piling in embankments. In: Proceedings of Baltic Piling Days 2012 in Tallinn (Estonia), electronically published
  • Hamann T. und Grabe J. (2012): Numerische Untersuchungen zur Rammung von Profilen in Böschungen. In: Proceedings der 4. VDI-Fachtagung Baudynamik 2012, VDI-Berichte 2160, S. 625-640
  • Hamann T. (2012): Numerische Untersuchungen zum Einfluss von Rammführungen auf das Verformungsverhalten von Spundbohlen während der Vibrationsrammung in einer Böschung. In: Tagungsband zur 32. Baugrundtagung 2012 in Mainz, Spezialsitzung 'Forum für junge Geotechnik-Ingenieure', S. 185-193
  • Henke S., Hamann T. und Grabe J. (2012): Numerische Untersuchungen zur Bodenverdichtung mittels Rütteldruckverfahren. Proc. des 2. Symposiums Baugrundverbesserung in der Geotechnik in 2012 Wien, herausgeg. von D. Adam und R.A. Herrmann, S. 209-228
  • Pichler T., Pucker T., Hamann T., Henke S. and Qiu G. (2012): High-Performance Abaqus simulations in soil mechanics reloaded - chances and frontiers. In: Proceedings of International Simulia Community Conference in Providense, Rhode Island/USA, pp. 237-266
  • Pucker T., Hamann T. und Henke S. (2011): Numerische Lösung von Fragestellungen mit großen Deformationen in der marinen Geotechnik. In: Tagungsband der Deutschen SIMULIA-Konferenz 2011 in Bamberg
  • Henke S., Hamann T. and Grabe J. (2011): Coupled Eulerian-Lagrangian simulation of the deep vibration compaction process as a plastodynamic problem. In: Proceedings of 8th International Conference on Structural Dynamics EURODYN 2011, pp. 482-489
  • Grabe J., Henke S., Hamann T., Mardfeldt B. und Kapusta J. (2011): Zum Einfluss der Herstellung der Widerlagerbaugruben der neuen Rethebrücke in Hamburg auf die bestehende Hubbrücke. In: Beiträge zum 26. Christian Veder Kolloquium - Tiefe Baugruben unter schwierigen Bedingungen, Mitteilungshefte der Gruppe Geotechnik Graz, Heft 40, S. 75-95
  • Pucker T., Hamann T. und Henke S. (2011): Numerische Untersuchung zur gesteuerten Einbringung von Pfählen. In: Tagungsband zum Pfahlsymposium 2011, Veröffentlichungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 94, S. 205-220
  • Grabe J., Henke S. und Hamann T. (2011): Zur numerischen Modellierung von Bodenverbesserungsmaßnahmen: Vibrationswalze, Impulsverdichter, Rüttelbohle und Rütteldruckverdichtung. In: Tagungsbeiträge zur 8. Österreichischen Geotechniktagung in Wien, Österreichischer Ingenieur- und Architekten-Verein, S. 259-270
  • Hamann T., Henke S. und Grabe J. (2010): Numerische Modellierung der Verdichtung rolliger Böden mittels Impulsverdichter, Rütteldruckverfahren und Rüttelbohle. In 'Baugrundverbesserung in der Geotechnik', Dietmar Adam und Richard Herrmann (Hrsg.), Institut für Geotechnik der Universität Siegen, S. 161-176
  • Kinzler S., Hamann T. und Grabe J. (2009): Numerische Untersuchungen zum geregelten Einbringen von Profilen. In: Veröffentlichungen des Instituts für Geotechnik und Bauebtrieb der TU Hamburg-Harburg, Heft 19, S. 99-125

Link to list of ongoing research projects
Link to list of completed research projects

Marine Safety Aspects Regarding Installation and Maintanance of Offshore Wind Turbines - Work Package 3: Collision of Ships With Gravity Foundations of Offshore Wind Turbines

Stand: 25.10.2023
Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

General information

  • Funding: Freie Hansestadt Hamburg (FHH, Cassirer-Stiftung)
  • Joint project (partners, see Projekt-Homepage)
  • Duration: 2012-2014 (36 months)
  • Staff B-5: David Osthoff
  • State: completed project, final report

Project description

Background and objectives 

This research project is concerned with ship and offshore plant safety, and focuses on problems that can arise in the context of offshore wind turbines (OWT) in the Baltic and North Seas. Safety problems in connection with ships can occur during the installation, operation, maintenance and decomposition phases of offshore plants. While these safety problems may involve various scenarios, the physical reasons will have a high level of similarity. A deep understanding of the physical phenomena and the interdisciplinary development of the simulation models in the numerical methods is crucial in generating efficient technical solutions for safety issues without disproportionally increasing project costs or time. The aim of this research project is to support the wind energy industry as well as national and international organizations by providing numerical methods in an effort to increase ship and offshore plant safety, to reduce the risks for humans, and to decrease the danger for environmental damage. The research project focuses on computational strategies devoted to the prognosis of accident event sequences and possible consequences of resulting damages. A database for capsizing and sinking accidents with ships will be developed in order to provide test cases for other research projects and to validate numerical methods currently under development. These methods can be applied to analyse accident scenarios and to improve the safety performance of new ships and offshore plant designs. The evaluation of numerical results can also be used to define various categories of preventive and operational measures that can decrease the likelihood of accidents as well as damages and their consequences. Preventive measures would change the design characteristics in such a way that a particular problem would not arise and/or would have less serious consequences. Operational measures would reduce the consequences of an accident. These measures can be implemented during an accident in order to decrease its magnitude and to minimize the consequences; for example, the development of evacuation plans depending on the extent of the damage incurred. A special feature of the planned numerical investigations is the simultaneous consideration of complex interaction between different phenomena. Examples included refer to the change in hydrostatic behaviour of offshore plants during installation, ship collision, global failure of ship structure due to local failure, and flooding simulation in rough seas under the influence of limited manoeuvring capabilities caused by damages of control devices in heavy weather conditions.

Six work packages on numerical simulation of dynamic ship and OWT behaviour in critical safety situations are included in the research program. A short summary of the 3rd work packages is given below:

Work package 3: Collision of ships with gravity foundations of offshore wind turbines (Grabe)

Gravity foundations are being developed in Germany as the preferred OWT foundation and will be used in the Baltic and North Seas in the near future. One of the necessary requirements for permission to operate a German OWT is an analysis of ship collisions with wind turbines in order to estimate both the risk of ship and wind turbine damage. The numerical modelling of the collision of a ship with an OWT is highly non-linear. FEM models will be developed considering inelastic modelling of ship structures, inelastic modelling of wind turbine structure including gravity foundation, inelastic and two-phase modelling of soil, modelling of ship movement due to surface waves, surface-based contact between ship and gravity foundation as well as gravity foundation and soil including the possibility of relative normal and tangential movements. The objectives of this work package are:

  1. Study of designs of gravity foundations and alternative foundation concepts for offshore wind turbines, especially with respect to risks caused by ship collision
  2. Analysis of risk of ship and foundation damage due to collision based on FEM analyses
  3. Design optimization of existing gravity foundations to minimize the risk of ship and foundation damage based on FEM analyses

Project relevant publications

  • Abdel-Maksoud M. u.a. (2014): Maritime Sefaty Aspects Regarding Installation and Maintanance of Offshore Wind Turbines. FHH-Abschlussbericht, Technische Universität Hamburg-Harburg (TUHH), Institut für Fluiddynamik und Schiffstheorie (federführend)

Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Berechnung von Offshore-Rammschall (BORA) - Teilprojekt Experimentelle und numerische Untersuchungen zur Schallquelle und zur Übertragung des Körperschalls

Status: 25.10.2023
Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Allgemeine Angaben

  • Mittelgeber: Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (BMU)
  • Förderkennzeichen: AZ 0325421A)
  • Forschungspartner: Institut für Modellierung und Berechnung (TUHH, federführend), Institut für Statik und Dynamik (Uni Hannover), Institut für Geowissenschaften (Uni Kiel)
  • Laufzeit: 2012-2015 (48 Monate)
  • Sachbearbeiter B-5: Katja Reimann, Matthias Schwarz, Alexander Chmelnizkij, Evelyn Heins

Projektbeschreibung

Bei der Schlag- und Vibrationsrammung von Pfählen für die Gründung von Offshore-Windenergieanlagen breiten sich Luftschall, Wasserschall und Körperschall im Meeresboden aus. Insbesondere der Hydroschall kann sich auf Meerersbewohner schädigend auswirken. In Deutschland ist deshalb in einem bestimmten Abstand zu Offshore-Rammarbeiten ein Grenzwert für den Hydroschallpegel vorgegeben. Um diesen einhalten zu können, werden momentan verschiedene technische Maßnahmen zur Schallreduktion untersucht. Ziel dieses Forschungsprojektes ist die Erstellung eines Modells zur Prognose des Hydroschalls. Dazu werden in der Nordsee Felduntersuchungen durchgeführt und verschiedene Simulationsmodelle für die Ausbreituntg von Hydroschall und Körperschall erarbeitet.

Bild: Foto eines Blasenschleiers um einen Monopile bei einem Feldversuch in der Nordsee

Link zur Projekt-Homepage

Projektrelevante Publikationen

  • Siegl K. (2017): Zur Pfahldynamik von gerammten Großrohrpfählen und der daraus resultierenden Wellenausbreitung in Wasser und im Meeresboden. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 40
  • Siegl K., Kanitz M., Grabe J. (2016): Entwicklung und Einsatz eines Messgerätes zur Erfassung der Bodenschallübertragung am Meeresgrund bei Offshore-Rammarbeiten. In: Tagungsband zum Fachseminar Messen in der Geotechnik 2016 in Braunschweig, Mitteilung des Instituts für Grundbau und Bodenmechanik der Technischen Universität Braunschweig, Band 101, S. 217–234
  • Reimann K., Grabe J. (2015): Dependency of wave fields in soil and water due to offshore pile driving on the approach of material behaviour. In: Proceedings of 3rd International Conference and Exhibition on Underwater Acoustics 2015 in Crete/Greece, pp. 501–506
  • Reimann K., Grabe J. (2015): Validation of sound source simulation due to offshore pile driving. In: Proceedings of 34th International Conference on Ocean, Offshore and Artic Engineering 2015 in St. John's (Canada), electronically published under paper No. OMAE2015-41164
  • Reimann K. und Grabe J. (2015): Zur Modellbildung der Schallquellquarakteristik von Offshore-Pfahlrammungen. In: Tagungsband zum Pfahl-Symposium 2015 in Braunschweig, Mitteilung des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft Nr. 99, S. 227–247
  • Reimann K. und Grabe J. (2014): Soil vibration due to offshore pile driving and induced underwater noise. Proceedings of 2nd International Conference and Exhibition on Underwater Acoustics 2014 in Rhodes/Greece, pp. 279–286
  • Grabe J., Chmelnizkij A. und Reimann K. (2014): Zur Reduktion von Unterwasserrammschall. HTG-Kongress in Berlin, S. 215-223
  • Reimann H. und J. Grabe (2014): Bodenbewegungen am Meeresboden beo Offshore-Rammarbeiten. In "Messen in der Geotechnik", Mitteilungen des Instituts für Grundbau und Bodenmechanik der TU Braunschweig, Heft 98, S. 141–160
  • Reimann K., Schwarz M. and Grabe J. (2013): Acoustic emissions due to offshore piling - field measurements at an offshore wind energy construction site. Proceedings of 23. International Ocean and Polar Engineering Conference (ISOPE) 2013 in Anchorage/USA, Vol. 1, pp. 150–156
  • Reimann K. and Grabe J. (2013): Field measurements of hydro sound emissions due to offshore piling at the construction site BARD Offshore 1. In: Proceedings of Conference on Maritime Energy (COME) 2013 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg-Harburg, Heft 26, pp. 345–359
  • von Estorff O., Heitmann K., Lippert S., Reimann K., Ruhnau M., Schwarz M. (2013): Unterwasser-Rammschall: Eine Herausforderung bei der Errichtung von Offshore-Windparks und für die numerische Simulation. In: Lärmbekämpfung – Zeitschrift für Akustik, Schallschutz und Schwingungstechnik, 8(2):61–71
  • Lippert T., Lippert S., von Estorff O. von, Milatz M. and Reimann K. (2012): Prediction of underwater sound due to pile driving for offshore wind frams – a challenge for numerical simulation. In: Proceedings of 41st International Congress and Exposition on Noise Control Engineering InterNoise 2012 in New York/USA
  • Lippert T., Lippert S., von Estorff O. von, Milatz M. and Reimann K. (2012): Prediction of pile driving induced underwater noise. In: Proceedings of 19th International Congress on Sound and Vibration ICSV19 in Vilnius/Lithunia
  • Milatz M., Reimann K. and Grabe J. (2012): Numerical simulations of hydro emissions due to offshore pile driving. Proceedings of 7th International Conference on Offshore Site Investigation and Geotechnics 2012 in London/UK, pp. 161–167, published by Society for Underwater Technology
  • Reimann K. und Grabe J. (2012): Modellierung von ramminduzierter Schallausbreitung in Wasser und Boden. In: Tagungsband zur 38. Jahrestagung für Akustik (DAGA) 2012 in Darmstadt
  • Henke S., Milatz M. und Grabe J. (2011): Numerical simulations of acoustic emissions due to offshore-pile installation. In: Proceedings Appl. Math. Mech., 11:629–630

Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Nutzung der oberflächennahen Geothermie im Hafen Hamburg

Stand: 25.10.2023
Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Allgemeine Angaben

  • Auftraggeber: Hamburg Port Authority (HPA)
  • Laufzeit: 2012 (6 Monate)
  • Sachbearbeiterin: Frauke Menzel
  • Status: Abgeschlossenes Projekt, Abschlussbericht intern

Projektbeschreibung

Machbarkeitsstudie zur Nutzung der oberflächennahen Geothermie am Central Terminal Steinwerder im Hafen Hamburg. Untersuchungen zur Installation von Wärmetauschern im Zuge der Verfüllung von Hafenbecken und zur Klimatisierung der Verkehrsflächen mittels Geothermie.

Projektrelevante Publikationen

  • Menzel F., Grabe J. und Kroggel N. (2012): Machbarkeitsstudie: Oberflächennahe Geothermie für Logistikflächen im Hamburger Hafen. In: Fachzeitschrift bbr – Sonderheft Geothermie, 63:14–21

Link zur Übersicht laufender Forschungsprojekte
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Machbarkeitsstudie für die Errichtung eines Versuchsdeichs als Voruntersuchung für das Forschungs- und Entwicklungsvorhaben 'Bestimmung der Widerstandsfähigkeit von Deichen

Status: 25.10.2023
Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Allgemeine Daten

  • Auftraggeber: Bundesanstalt für Wasserbau (BAW)
  • Partner: Institut für Wasserbau der TU Hamburg-Harburg, Kooperation mit WSV
  • Laufzeit: 2013 (3 Monate)
  • Sachbearbeiterin: Désirée Plenker
  • Status: Abgeschlossenes Projekt, Abschlussbericht intern

Projektbeschreibung

Für die wissenschaftliche Beurteilung der Widerstandsfähigkeit von Deichdeckschichtmaterialien, in Abhängigkeit von Bodenstrukturveränderungen infolge Alterung, saisonalen Witterungseinflüssen und Bioturbation, ist die Errichtung eines Versuchsdeichs geplant. An zwei Abschnitten mit unterschiedlichen Deckschichtmaterialien (Klei und Baggergut) sollen dafür über einen Zeitraum von mindestens 10 Jahren, die Bodenkennwerte sowie Grasnarbenqualität und deren Einfluss auf die Erosionsstabilität untersucht werden. Die Einflüsse der verschiedenen Parameter auf die Widerstandsfähigkeit des Deichs werden später wissenschaftlich formuliert und dienen als Eingangsdaten für eine numerische Modellierung. In der numerischen Simulation sollen die Forschungsergebnisse auf der Widerstandsseite, den Belastungen aus Hochwasserereignissen gegenübergestellt und eine Bemessung des Bauwerks unter Berücksichtigung aller simultanen Einwirkungen ermöglicht werden. Bislang beruht die Nachweisführung auf einzelnen ungekoppelten analytischen Ansätzen.

Im Rahmen der Machbarkeitsstudie wurde die Errichtung des Versuchsdeichs geplant und organisiert. Weiterhin galt es ein Messkonzept hinsichtlich geotechnischer und wasserbaulicher Fragestellungen zu erarbeiten und dieses auf Umsetzbarkeit und wissenschaftliche Verwertbarkeit zu prüfen.

Projektrelevante Publikation

  •  Abschlussbericht (intern)

Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Nutzung dynamischer geotechnischer Systeme zur sorptionsgestützten nachhaltigen Klimatisierung (Dyn-GSGK)

Stand: 16.07.2020 (hst)
Link zur Übersicht laufender Forschungsprojekte
Link zur Übersicht abgeschlossener Forschungsprojekte

Allgemeine Angaben

  • Mittelgeber: Bundesministerium für Wirtschaft und Energie (BMWi)
  • Projektträger: Projektträger Jülich (PtJ)
  • Förderkennzeichen: AZ 03ET1421A
  • Forschungspartner: Institut für Thermofluiddynamik der TUHH (Prof. Gerhard Schmitz)
  • Laufzeit: 16.09.2016 bis 15.09.2019 (kostenneutral verlängert bis 31.10.2020)
  • Sachbearbeiter B-5: Matthias Schuck
  • Status: Abgeschlossenes Projekt, BMWi-Abschlussbericht

Projektbeschreibung

Das Folgeprojekt Nutzung dynamischer geothermischer Systeme zur sorptionsgestütztennachhaltigen Klimatisierung (Dyn-GSGK) baut auf dem erfolgreichen BMWi-Projekt Ezienzsteigerung der geothermisch- und sorptionsgestützten Klimaanlage (E-GSGK) auf. Ziel ist es, eine weitestgehend auf erneuerbaren Energien basierende Klimatisierung für den Grund- und insbesondere den Spitzenlastfall zu entwickeln. Durch die erstmalige Verwendung von dynamisch regelbaren Erdreichwärmeübertragern (EWÜn) kann auf eine Überdimensionierung des geothermischen Systems verzichtet werden. Sowohl die an der TUHH selbst entwickelten innovativen EWÜ als auch die sorptionsgestützte Klimaanlage sowie deren Zusammenspiel sollen dabei anhand einer Pilotanlage detailliert untersucht werden. Die Trennung von Kühlung und Entfeuchtung reduziert dabei zunächst die Lastspitzen des Kältebedarfs, die verbleibenden Spitzen können dann in ausreichender Weise durch die innovativen EWÜ gedeckt werden. Dies ermöglicht eine wirtschaftliche Konkurrenzfähigkeit gegenüber konventionellen Lösungen, da auf eine elektrische Kältemaschine komplett verzichtet werden kann. Dadurch haben diese Systeme in Zukunft das Potenzial, fflächendeckend eingesetzt zu werden und einen erheblichen Beitrag zur Reduzierung von Treibhausgasen zu leisten. Die lückenlos zuverlässige Gewährleistung thermischen Komforts und die Reduktion des CO2 -Ausstoßes stellen bei einer solchen Anlage keinen Widerspruch mehr dar.

Die gewonnenen Erkenntnisse über das Betriebsverhalten und die Eigenschaften eines Luftinjektions-Erdreichwärmeübertragers (LI-EWÜs) als auch der sorptiven Entfeuchtung der Außenluft und der verbesserten Steuerung einer geothermisch- und sorptionsgestützten Klimaanlage fließen direkt in das Folgeprojekt ein. Hierbei besteht ein besonderer Fokus auf der Untersuchung der Interaktion von mehreren LI-EWÜn untereinander als auch in Kombination mit konventionellen EWÜn. Das im Vorgängerprojekt beobachtete sehr schnelle dynamische Verhalten der LI-EWÜ wird intensiv untersucht und für den energieeffizienten und wirtschaftlichen Betrieb einer Klimatisierung optimiert. Die zusätzliche Regelgröße auf Seiten der Geothermie steigert die Flexibilität der Klimaanlage dabei erheblich.

Projektrelevante Publikationen

  • Schuck M. (2016): Steigerung der Entzugsleistung von Erdwärmesonden durch Luftinjektion. In: Tagungsband zur 34. Baugrundtagung 2016 in Bielefeld – Forum für junge Geotechnik-Ingenieure, S. 199–204
  • Schuck M., Speerforck A., Niemann P., Grabe J., Schmitz G. (2016): Klimatisierung von Gebäuden mit hohen Komfortanforderungen unter Verwendung regenerativer Energie. In: Bauingenieur 91, S. 288–296

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Subsequent load-bearing capacity increase of offshore pile foundations - subproject Load-bearing capacity increase of piles through targeted subsequent soil plugging (TOP)

Stand: 06.12.2024
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General data

  • Funding: Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit (BMU)
  • Project management: Projektträger Jülich (PtJ), funding code AZ 0324048A
  • Research partner: Bundesanstalt für Materialforschung und -prüfung (BAM) in Berlin (Fachbereich 7.2, Dr.-Ing. Mathias Baeßler)
  • Duration: 01.09.2016 to 31.08.2019 (cost-neutral extension to 31.10.2020)
  • Researcher: Dominik Zobel
  • Status: Completed project, final report

Project description

Building on the DFG project HE 5445/2-1 “Investigations into soil plugging formation”, field tests are being conducted to investigate how the axial load-bearing capacity can be increased by subsequently plugging steel pipes driven into the ground. The field tests were carried out on the test site of the project partner BAM in Berlin.

 

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Suction Installation of Maritime Structures (SIMS) - hydraulic-mechanical coupled numerical modelling

Status: 06.12.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/26-1 and 26-2
  • Duration: 2016 to 2020 (44 months)
  • Researcher: Marc Stapelfeldt
  • Status: Completed project, final report, PhD thesis

Project description

As part of the research project, the installation of suction buckets, which are installed into the seabed consisting of saturated sand using negative pressure, was investigated, their load-bearing behavior taking into account the influence of production and the extraction from the seabed supported by overpressure. Building on existing results of model tests on the insertion and extraction process and the load-bearing behaviour, additional model tests were carried out in a geotechnical centrifuge to investigate the drainage conditions of the soil during insertion and extraction. Numerical simulations of the insertion and extraction process and the load-bearing behavior using the Finite Element Method (FEM) helped to better understand the mechanically and hydraulically coupled processes in the soil, estimate the influence of the insertion process on the subsequent load-bearing behavior and investigate the formation of possible water permeabilities between the bucket and the soil. An approach that already exists at the applicant's institute was used to model the mechanically and hydraulically coupled behavior of saturated sand. To represent the mechanically-hydraulically coupled contact behavior between bucket and soil, the necessary constitutive equations were implemented as a contact model within a user routine. The contact model and the FEM model for simulating the insertion and extraction process as well as the load-bearing behavior were validated and used for a parameter study to investigate various influences.

Project-relevant publications

  • Stapelfeldt M. (2021): Suction Installation of Maritime Structures (SIMS) - hydraulic-mechanical coupled numerical modeling. Dissertation. Technische Universität Hamburg (TUHH), DOI: 10.15480/882.327
  • Stapelfeldt M., Chmelnizkij A. and J. Grabe (2019): Numerical investigations on bearing capacity analyses of shallow foundations in small and large deformation. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 19, pp. 115–121, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Stapelfeldt M., Bienen B. and Grabe J. (2018): Centrifuge tests investigating the effect of suction caisson installation in dense sand on the state of the soil plug. In: Proceedings of 9th International Conference on Physical Modelling in Geotechnics (ICPMG) in London/UK, A. McNamara et al. (eds.), CRC Press, pp. 559
  • Stapelfeldt M., Bienen B. und J. Grabe (2017): Advanced approaches for coupled deformation-seepage-analyses of suction caisson installation. In: Proceedings of International Conference on Ocean Offshore & Artic Engineering (OMAE) 2017 in Trondheim/Norway, electronically published under OMAE2017-61378
  • Stapelfeldt M. und Grabe J. (2017): The advantages of suction bucket foundations regarding decommissioning and removal. In: Proceedings of Conference on Maritime Energy (COME) 2017 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg, Heft 38, S. 195–208
  • Stapelfeldt M., Bubel J., Grabe J. (2015): Numerical investigation of the installation process and the bearing capacity of suction bucket foundations. In: Proceedings of 34th International Conference on Ocean, Offshore and Artic Engineering 2015 in St. John's (Canada), electronically published under paper No. OMAE2015-41808

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Influence of uncertain soil models on the construction and design of geotechnical structures

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/27-1 in the framework of DFG Priority Programme SPP 1886 “Polymorph uncertainty modelling for the numerical design of structures”
  • Duration: 2016 to 2019 (36 months)
  • Staff: Andre Vogel (27 months), Timon Burgwedel (9 months)
  • Status: Completed project, interim report and continuation proposal

Project description

As part of the research project, the scatter of soil state variables (stress state and void ratio) and their influence on the result of Cone Penetration Tests (CPT) and, furthermore, on the design of geotechnical structures was investigated. Using existing CPT data in a geotechnically well-explored test field in Hamburg, an inverse parameter determination was carried out using numerical optimization. This allows the vertical stress and density distribution in the test field to be deduced by numerical simulation of the CPTs. The soil models derived in this way were used for further numerical simulations, for example of full displacement bored piles in the test area, for which measurement data is also available. From the numerical and measured results, correlations between the peak resistance of the CPT probe and the soil state variables were investigated and further developed. This also included a correlation of machine parameters during the installation of the full displacement bored piles with the soil properties and with the expected pile load-bearing capacity. Overall, the influence of data scatter and uncertainty on the numerical results and on the design was investigated.

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Increasing the load-bearing capacity of geotechnical structures by means of shear zone strengthening (TGTSV)

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), projects No. GR 1024/23-1, 23-2, and 23-3
  • Duration: 2016 to 2019 (24 months), 2021 to 2023 (24 months), 2023 to 2025 (24 months)
  • Staff: Karlotta Seitz (21-1), Elnaz Hadjiloo (21-2 and 21-3)
  • Status: Ongoing project, paused until 31.08.2025

Project description GR 1024/23-1

The subject of the research project was the investigation of limit states of the load-bearing capacity of geotechnical structures with regard to the increase in the load-bearing capacity. The focus here is on the shear zones that form in the ground. An innovative approach to increasing the load-bearing capacity of geotechnical structures was investigated: the strenghtening of shear zones. Based on the idea of ​​a decisive failure mechanism with an associated load-bearing capacity, the load-bearing capacity can be increased if this mechanism is deliberately hindered by shear zone strengthening. The shear zones and load-bearing capacities of two geotechnical structures were determined in numerical simulations. A method was developed that enables an automated numerical simulation of the strengthening of shear zones. The method was developed on the basis of previously developed concepts for the numerical optimization of geotechnical structures in the serviceability state. The increase in load-bearing capacity could thus be determined numerically, as well as the mechanical stress to which the strengthening material is exposed. 1g model tests with shear zone strengthening were then carried out. In preliminary tests, suitable materials were selected and a method for shear zone strengthening was developed for the model scale. The findings were applied to ng model tests in a geotechnical centrifuge and thus the transferability to a real stress level was checked.

Project description GR 1024/23-2

...

Project description GR 1024/23-3

...

Project relevant publications

  • Seitz K. (2021): Zur Topologieoptimierung von geotechnischen Strukturen und zur Tragfähigkeitssteigerung des Baugrunds durch Scherfugenverfestigung. PhD thesis. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 45
  • Hadjiloo E., Grabe J. (2023): Numerical shear band strengthening with contact modelling for the increase of load capacity of geotechnical structures. In: Proceedings of 5th International Conference on Geotechnics for Sistainable Infrastructure Development 2023 in Hanoi/Vietnam, Phung Duc Long, Nguyen Tien Dung (eds), Construction Publishing House, pp. 272 (abstract)
  • Hadjiloo E., Grabe J. (2023): Investigation of shear band strengthening by using different strengthening criteria. In: Proceedings of 8th International Symposium on Deformation Characteristics of Geomaterials 2023 in Porto (IS-PORTO), E3S Web of Conferences, Vol. 544, No. 11002, DOI: 10.1051/e3sconf/202454411002
  • E. Hadjiloo, Grabe J. (2022): Erste Ansätze zur Scherfugenverfestigung geotechnischer Konstruktionen mittels Scherfugenverfestigung. In: Tagungsband zum Workshop Numerische Methoden in der Geotechnik 2022 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg, Heft 53, S. 201–205
  • Seitz K.-F. and J. Grabe (2018): 1g-modelling of limit load increase due to shear band enhancement. In: Proceedings of 9th International Conference on Physical Modelling in Geotechnics (ICPMG) in London/UK, A. McNamara et al. (eds.), CRC Press, pp. 1451
  • Seitz K.-F. and J. Grabe (2018): Numerical modelling of limit load increase due to shear band enhancement. In: Proceedings of 9th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE) in Porto/Portugal, Vol. 2, pp. 1391–1398, CRC Press, Taylor & Francis Group, ed. by A.S. Cardose et al.
  • Seitz K.-F., Grabe J. (2018): Einsatzmöglichkeiten der multikriteriellen Optimierung im digitalen Bauen. In: Digitale Infrastruktur und Geotechnik 2018, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg, Heft 42, S. 169–181
  • Grabe J. und Seitz K.-F. (2016): Optimization of geotechnical structures for states of serviceability and ultimate loads. In Insights and Innovations in Structural Engineering, Mechanics and Computation (ed. A. Zingoni), Taylor & Francis Group, London, 2016, pp. 2048–2053. Proceedings of 6th International Conference on Structural Engineering, Mechanics and Computation (SEMC 2016) 2016 in Cape Town, South Africa

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Investigations into the implementation of vibro-pressure processes and the production of vibro-compacted columns and geotextile-coated columns

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH), Postdoc scholarship
  • Duration: 01.10.2016 to 30.09.2017 (12 months)
  • Staff: Sparsha Nagula Sinduri
  • Status: Completed project, PhD thesis published in institute's series (Vol. 50)

Project description

The aim was to determine the research needs in the field of soil compaction using vibrocompaction methods, vibrocompaction columns and geotextile-coated columns by evaluating field investigations and by using our own numerical simulations based on the Finite Element Method (FEM) using the Coupled Eulerian-Lagrangian (CEL) approach.

Project relevant publications

  • Nagula S. (2021): PhD thesis see DAAD project
  • Chmelnizkij A., Nagula S. and J. Grabe (2017): Numerical simulation of deep vibration compaction in Abaqus/CEL and MPM. In Proceedings of 1st International Conference on the Material Point Method 2017 in Delft/The Netherlands, Elesevier Procedia, Series on Procedia Engineering Vol. 175, A. Rohe et al. (eds.), pp. 302-309
  • Nagula S. and J. Grabe (2017): 2-phase dynamic simulation of deep sand compaction to reduce liquefaction. In: Proceedings of 10th International Conference on Structural Dynamics (EURODYN) 2017 in Rome/Italy, Elsevier Procedia, Series on Procedia Engineering Vol. 199, F. Vestroni et al. (eds.), pp. 2396-2401
  • Nagula S. and J. Grabe (2017): Determination of intergranular strain parameters and their dependence on properties of grain assemblies. In: Proceedings of International Workshop on Advances in Laboratory Testing and Modelling of Soils and Shales (ATMSS) 2017 in Villars-sur-Ollon/Switzerland, A. Ferrari and L. Laloui (eds.), Springer Series in Geomechanics and Geoengineering, pp. 395-404
  • Grabe J., Zobel D., Nagula S. und A. Chmelnizkij (2017): Zur numerischen Modellierung von dynamischen Randwertproblemen. In: BAWMitteilungen Nr. 101 "Natürliche, künstliche und virtuelle Stoffe in der Geotechnik", S. 59-72, Bundesanstalt für Wasserbau

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Optimization of construction machinery and construction processes

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH), Werner-Möbius-Stiftung
  • Duration: 15.10.2014 to 14.10.2017
  • Staff: Dominik Zobel (15.10.2014 to 31.08.2016), Marius Milatz (16.05.2015 to 15.08.2018)
  • Status: Completed project

Project description

As part of the project, the optimization of a number of construction machines and construction methods was investigated:

Project relevant publications

  • Milatz M., Grabe J. und M.M. Delle (2019): Bewertung von Verklebungen und Werkzeugverschleiß im Lockergestein anhand von Modellversuchen. In: Geotechnik, DOI: 10.1002/gete.201800017
  • Zobel D., Milatz M., Grabe J. (2017): Modellversuche zur Stabilität von Baumaschinen mit hohem Schwerpunkt. In: Geotechnik 41(1):40–46, DOI: 10.1002/gete.201700009
  • Grabe J., Zobel D., Nagula S. und A. Chmelnizkij (2017): Zur numerischen Modellierung von dynamischen Randwertproblemen. In: BAWMitteilungen Nr. 101 "Natürliche, künstliche und virtuelle Stoffe in der Geotechnik", S. 59–72, Bundesanstalt für Wasserbau
  • Grabe J., Milatz M., Zobel D. und M. Liebetrau (2017): Zur Standsicherheit von Spezialtiefbaumaschinen auf nachgiebigem Untergrund. Tagungsband zur 11. Österreichischen Geotechniktagung 2017 in Wien, Österreichischer Ingenieur- und Architekten-Verein (Hrsg.), S. 305–316

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Investigation of failure of sheet pile interlocks due to installation of combined sheet pile walls

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/18-1
  • Duration: 2014 to 2017 (36 months)
  • Staff: David Osthoff
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 43)

Project description

Steel sheet piles are used in geotechnics for retaining walls of excavation pits and quay wall constructions, among other things. The design of such sheet piles is based on static calculations for construction and operating conditions. Installation-related stresses due to indentation, vibratory driving, and impact driving of the steel profiles into the subsoil are not taken into account. In construction practice, particularly in the highly stressed composite sheet piles of modern quay wall constructions, damage in the form of failure of the sheet pile interlocks is often evident. Examples include the quay wall constructions in Rotterdam (Maasvlakte I, 1972), Bremerhaven (Neue Kaiserschleuse, 2009) and the recent damage to the quay construction in Wilhelmshaven (JadeWeserPort, 2012). As part of the research project, the total load on steel sheet piles was investigated, taking manufacturing-related influences into account on the basis of numerical modelling. The subject of the investigations included the guidance of pile driving equipment, the heat development in sheet pile interlocks during piling and the spatial distribution of earth and water pressure in combined steel sheet pile walls. The aim of the project was to develop design rules to reduce sheet pile damage in future construction projects.

Project relevant publications

  • Osthoff D. (2018): Zur Ursache von Schlosssprengungen und zu einbringbedingten Lageabweichungen von Spundwänden. Dissertation. Technische Universität Hamburg-Harburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 43
  • Grabe J. und D. Osthoff (2018): Toleranzanforderungen bei langen kombinierten Spundwänden. In: Bautechnik 95(9):658–662, DOI: 10.1002/bate.201800020
  • Osthoff D. (2018): Messtechnische Begleitung des vibrierenden Einbringens von Stahlspundwandprofilen. In: Geotechnik 41(2):84–98, DOI: 10.1002/gete.201700013
  • Osthoff D. und J. Grabe (2018): Deformational behaviour of steel sheet piles during jacking. In: Computers and Geotechnics 101:1–10, DOI: 10.1016/j.compgeo.2018.04.014
  • Osthoff D. und J. Grabe (2017): Zu den Ursachen von Schlosssprengungen bei kombinierten Spundwänden. In: HTG Hafenbautechnische Gesellschaft (Hg.): HTG-Kongress, Duisburg, S. 39–49
  • Osthoff D. (2017): Messtechnische Begleitung einer Spundwandvibrationsrammung. In: J. Stahlmann (Hg.): Stahl im Wasserbau. Unter Mitarbeit von M. Rosenberg. Braunschweig (Mitteilungen des Institutes für Grundbau und Bodenmechanik Technische Universität Braunschweig, 103), S. 71–88
  • Grabe J. und D. Osthoff (2017): Zum Tragverhalten von Spundwänden unter Berücksichtigung von Lageimperfektionen. In: Veröffentlichungen Stahlspundwände - Planung und Anwendung, Ausgabe 2017, Wirtschaftsvereinigung Stahl (Hrsg.)
  • Osthoff D. und J. Grabe (2016): Untersuchung von Schlosssprengungen an ausgeführten Ufereinfassungen mit kombinierten Spundwänden. In: Bautechnik 93(12):912–924, DOI: 10.1002/bate.201600061
  • Osthoff D. (2016): Numerische Untersuchungen zum Tragverhalten von Zwischenbohlen kombinierter Spundwände unter Berücksichtigung von Rammimperfektionen. In: Tagungsband zur 34. Baugrundtagung 2016 in Bielefeld - Forum für junge Geotechnik-Ingenieure, S. 121–129
  • Osthoff D., Pucker, T. Grabe J. (2015): Untersuchungen zur Beanspruchung von Spundwandprofilen durch den Einbringprozess. In: Tagungsband zum HTG-Kongress 2015 in Bremen, S. 185–196

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Hydraulic loosening of soils

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project No. GR 1024/21-1
  • Duration: 2014 to 2016 (24 months)
  • Staff: Bozhana Kovac
  • Status: Completer project, interim report and continuation proposal, PhD thesis published in institute's series (Vol. 39)

Project description

Hydraulic loosening of soils plays a role in many geotechnical problems. One example is the jet grouting method, which uses high-pressure injection to grout soil. Although the method is versatile, there are often difficulties in accurately recording the effect of the high-pressure jet in the soil and in determining the diameter of the jet grouting elements, which depends on many factors, namely:

  • properties of soils (relative density of non-cohesive soils, consistency of cohesive soils),
  • properties of the fluid jet (composition, pressure),
  • and machine parameters (nozzle geometry, nozzle pressure, pulling speed and rotation speed).

Loosening the soil using a water jet is also used in the increasingly important field of offshore wind energy, namely in the installation of submarine cables. It is used to place the cable in the soil at a certain depth so that external influences, damage, and negative effects on marine flora and fauna are excluded.

An overarching goal of the research project was to map and record the processes taking place in the soil during jet grouting, as well as the factors influencing the range of the jet in the soil using numerical simulations. The simulation models used for this purpose are based on the Smoothed Particle Hydrodynamics Method (SPH), a mesh-free numerical method that has proven itself in the field of physics and fluid dynamics. The SPH has already been successfully used to calculate multiphase flows as well as flows with free surfaces and solids-rich flows. Recent research results indicate that the method is also suitable in computational soil mechanics. As part of the project, a material model and a boundary condition for soil were implemented and validated in the SPH-code GADGET-H2O and simulations of the jet grouting were then carried out. The results provided a conclusion about the range of the fluid jet and the relationships between various soil and process parameters, and thus made a contribution to increasing the economic efficiency and improving the quality assurance of geotechnical processes.

Project relevant publications

  • Amicarelli A.. Kocak B., Sibilla S. and J. Grabe (2017): A 3D smoothed particle hydrodynamics model for erosional dam-break floods, In: International Journal of Computational Fluid Dynamics 31(10):413–434, DOI: 10.1080/10618562.2017.1422731
  • Kocak B. (2017): Zur numerischen Modellierung von hydraulisch-mechanisch gekoppelten Prozessen in gesättigten granularen Böden mittels Smoothed Particle Hydrodynamics. PhD thesis. Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg, Heft 39
  • Amicarelli A., Agate G., Stefanova B., Sibilla S. und J. Grabe (2016): A SPH model for dike overtopping and dam liquefaction with bed-load transport, bottom drag and mobile boundaries. In: Proceedings of 11th SPHERIC ERCOFTAC International Workshop SPHERIC 2016 - ERCOFTACT Conference in Munich/Germany, X. Hu (ed.), S. 424–431
  • Stefanova B. und Grabe J. (2015): Numerische Simulation der Boden-Wasser-Interaktion mittels eines Zweiphasenmodells im Rahmen der Smoothed Particle Hydrodynamics (SPH). In: Numerische Methoden in der Geotechnik, Bundesanstalt für Wasserbau (Hrsg.), BAWMitteilungen Nr. 98, S. 117–128
  • Stefanova B. (2015): Simulations of water-soil interaction using Smoothed Particle Hydrodynamics. In: Proceedings of Workshop on Numerical Methods of Water-Soil Boundary Layers under Currents and Waves (Morphodynamics 2015), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg-Harburg, Heft 33, S. 3–18
  • Grabe J., Stefanova B. (2015): Numerical modeling of saturated soils based on Smoothed Particle Hydrodynamics (SPH) - Part 2: Coupled analysis. In: Geotechnik 38(3):218-229, DOI:10.1002/gete.201400027
  • Stefanova B., Grabe J. (2014): Numerical modeling of the flow and seabed erosion around a pipeline using Smoothed Particle Hydrodynamics (SPH). In: Proceedings of 7th International Conference on Scour and Erosion 2014 in Perth/Australia, CRC Press, ed. by L. Cheng, S. Drapper and H. An, pp. 725–732
  • Grabe J., Stefanova B. (2014): Large displacements and fluidization of sand due to seepage. In: Proceedings of 7th International Conference on Scour and Erosion 2014 in Perth/Australia, CRC Press, ed. by L. Cheng, S. Drapper and H. An, pp. 411–418
  • Grabe J. und Stefanova B. (2014): Numerical modeling of saturated soils, based on Smoothed Particle Hydrodynamics (SPH) - Part 1: Seepage analysis. In: Geotechnik 37(3):191–197
  • Stefanova B. und Grabe J. (2014): SPH model of water jet erosion in granular soils with a boundary layer of liquified soil. In: Proceedings of International Symposium on Geomechanics from Micro to Macro 2014 in Cambridge/UK, pp. 999–1004, Soga et al. (eds.)

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Development of bionic dental implants using structural optimization

Status: 26.11.2024
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General data

  • Funding: Forschungszentrum Medizintechnik Hamburg (fmthh)
  • Project partner: T. Köhne (Universitätsklinikum Hamburg-Eppendorf, UKE)
  • Duration: 01.08.2015 to 31.12.2016 (6 months)
  • Staff: Karlotta Seitz
  • Status: Completed project, internal report

Project description

Bionics researches biological construction and development principles and applies them to the design of medical products. Although around 1 million dental implants are placed every year in Germany alone, there is no agreement on the ideal shape, size, and number of implants, as the development principles of the human tooth roots to be replaced are unclear. The aim of this funding application was to transfer geotechnical topology optimization models to the human periodontium in order to understand the basic mechanisms of tooth root formation.

To create the model, the dimensions of the tooth root and jawbone were determined using digital volume tomography of patients with physiological bone conditions. A simplified finite element model was created from the averaged values. The material properties of the tooth and alveolar bone were determined on human autopsy specimens using micro Computed Tomography and nanoindentation.

The Solid Isotropic Material with Penalization (SIMP) method was not suitable for simulating the tooth root. The Soft Kill Option (SKO) method, on the other hand, showed good optimization results. The SKO method was the first to create a numerical model that describes root formation in three dimensions without any shape specifications.

Project relevant publications

  • Seitz K.-F., Grabe J. and T. Köhne (2018): A three-dimensional typology optimization model for tooth-root morphology. In: Computer Methods in Biomechanics and Biomedical Engineering 21(2):177–185, DOI: 10.1080/10255842.2018.1431778
  • Köhne T. und K. Seitz (2017): Entwicklung bionischer Zahnimplantate mittels Strukturoptimierung. fmthh-Abschlussbericht

Project relevant student works

  • Schaupeter E. (2017): Studie zur Anwendung von Strukturoptimierungsverfahren für bionische Zahnimplantate. Bachelor thesis
  • Bröhan, J. (2016): Studie zur Anwendung von Strukturoptimierungsverfahren auf Zahnwurzeln. Bachelor thesis
  • Engel, T. (2016): Studie zu bionischen Gründungen am Beispiel von Zahnwurzeln im dreidimensionalen Modell. Bachelor thesis
  • Edding, E. M. (2016): Studie zur Optimierung von Gründungen am Beispiel von Zahnwurzeln. Bachelor thesis
  • Sander, M. (2015): Studie zu bionischen Gründungen am Beispiel von Zahnwurzeln. Bachelor thesis

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Numerical process optimization

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2016 to 2020 (48 months)
  • Staff: Jan Onne Backhaus
  • Status: Completed project, PhD thesis published in institute's series (Vol. 49)

Project description

At the beginning of the project, the focus was on the topic of “Lean Construction”, then the topics “Numerical methods for predicting project duration” and “Numerical optimization methods for project planning” were addressed.

Project relevant publications

  • Backhaus J. O. (2021): A methodology for the numeric time-cost forcecast and paretro optimization of large injection projects in tunneling. PhD thesis. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 49
  • Backhaus J.O.  (2020): Bauzeitenvorhersage von Injektionen im Tunnelbau. In: Bautechnik 97, pp. 1–11, DOI: 10.1002/bate.201900093
  • Backhaus J.O. und M.H. Dahm (2020): Einblick in den Stand der Implementierung von Lean Construction Ansätzen in ausgewählten deutschen Bauunternehmen – Ergebnisse einer qualitativen Studie. In: Bauingenieur 02/2020, pp. 64–72
  • Backhaus J.O. (2019): Vorhersage des Injektionsvolumens einer Tunnelbaustelle unter Verwendung von Markov Ketten. In: Tagungsband zum 30. Treffen der Assistenten der Bereiche Bauwirtschaft, Baubetrieb und    Bauverfahrenstechnik (BBB-Assistententreffen) 2019 in Karlsruhe, pp. 6–22
  • Backhaus J.O. und J. Grabe (2018): Numerisch basierte Prozessanalyse. In: Digitale Infrastruktur und Geotechnik 2018, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg, Heft 42, pp. 253–270
  • Backhaus J.O. (2018): Digitale Optimierung der Bauplanung. In: Tagungsband zum 29. Treffen der Assistenten der Bereiche Bauwirtschaft, Baubetrieb und Bauverfahrenstechnik (BBB-Assistententreffen) 2018 in Braunschweig, pp. 23–33

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Development of a Subgrade Reaction Model for piles under lateral loading with variable load direction

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 2018 to 2019
  • Staff: Anne Hagemann
  • Status: Completed project, successor DFG projects GR 1024/37-1 and 37-2

Project description

The project is based on the further development of a hypoplastic Subgrade Reaction Model for single piles under lateral loading. The extensions include the consideration of the soil density (pycnotropy), the stiffness at small strain (small strain stiffness) and the time-varying load direction to take pile drift into account. The work will be continued from 2019 as part of the DFG project GR 1024/37-2 and GR 1024/37-2 as well as WI 3810/5-1 and WI 3810/5-2 “Holistic approach for the design of single piles and pile groups”.

Project relevant publications

  • Hagemann A. und J. Grabe (2019): Schwingungsverhalten einer Offshore-Windenergieanlage unter dynamischer Anregung. In: Tagungsband zur Fachsektionstagung Geotechnik 2019 in Würzburg, Deutsche Gesellschaft für Geotechnik e. V. (Hrsg.), S. 352
  • Carstensen E., Pucker T. und J. Grabe (2018): Numerical model to predict the displacment of piles under cyclic lateral loading using a new hypoplastic spring element. In: Computers and geotechnics 101:217–223, DOI: 10.1016/j.compgeo.2018.05.001

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Evaluation of feasibility of a particle sensor for micromechanical detection of unsteady transport processes at soil-water interface

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH), collaborative I3 project 2018
  • Project partner: Prof. Hoc Khiem Trieu, Institut für Mikrosystemtechnik, TUHH
  • Duration: 2018 to 2019 (6 months)
  • Staff: Timon Burgwedel
  • Status: Completed project, internal report

Project description

Feasibility study to develop a miniaturized particle that can be used for model tests at the interface between surface water and soil and can measure and store the fluid pressure and acceleration of the particle.

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Experimental and numerical investigation of wetting of porous media

Experimental and numerical investigation of wetting of porous media

Status: 26.11.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH), collaborative I3 project 2018
  • Project partner: Prof. Alexander Düster, Institut für Konstruktion und Festigkeit von Schiffen, TUHH
  • Duration: 2018 (6 months)
  • Staff: Tom Törzs
  • Status: Completed project, internal report

Project description

The main objective of this project, which arises from numerous similarities in the applicants' research interests and methods, was to prepare a joint DFG application to investigate the influence of wetting of porous materials on their mechanical behaviour. To this end, appropriate preliminary work of an experimental and numerical nature must be carried out, which is outlined in Section 4. It is planned to publish the results obtained as part of this application together, in order to be able to document the applicants' corresponding preliminary work. The global objectives of the planned DFG research application, which should also serve as a guide for the current start-up project, can be formulated as follows:

  • To gain a better understanding of the micromechanical deformation and fracture behaviour of porous composite materials that are formed by wetting a porous material with at least one other phase;
  • Development and application of methods to generate numerical models based on Computed Tomography (CT);
  • Bridging the gap between the microscopic and macroscopic material behaviour of porous composite materials.

The project resulted in the DFG proposal GR 1024/41-1 and DU 405/17-1 “Numerical modelling of partially cemented soils in stagnation domain”, which was approved in 2020.

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Vibroflotation as liquefaction mitigation measure

Status: 26.11.2024
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General data

  • Funding: Deutscher Akademischer Austauschdienst (DAAD)
  • Duration: 01.10.2016 to 30.09.2020
  • Staff: Sparsha Nagula Sinduri
  • Status: Completed project, PhD thesis published in institute's series (Vol. 50)

Project description

Situation  The current world population ranges around 7 Billion and is ever-increasing; the rising population has created huge demand of land for various infrastructure facilities. This has pushed the engineering community to use land which previously in history was considered unsuitable for any construction. Granular soils are mainly improved by imparting mechanical forces which lead to densification. The vibroflotation method is an established ground improvement technique for granular soils. This technique is used to improve the properties of loose to medium dense granular soils by compacting deep layers of the soil and therefore reducing settlements and increasing the vertical bearing capacity of foundations. Additionally, it also aids in liquefaction mitigation.

Objectives  The major outlook of the proposed research work is numerical simulation of vibroflotation method in order to develop an insight on the impact of the technique on the surrounding soil. The proposed research work is twofold, first being validation of numerical simulation based on the results of model tests and field measurements and second being parametric study and optimisation of the technique to improve its effectiveness and cost reduction. The research also aims at studying the effectiveness of vibroflotation method to serve as liquefaction mitigation measure.

Work plan  The vibroflotation technique is numerically simulated in Coupled Eulerian and Lagrangian (CEL) computational framework. Model tests are carried out with indigenously fabricated model vibrator. The model vibrator is scaled down version of prototype vibrator used on field and is used to study the effects of vibroflotation in dry sand under controlled laboratory environment. The effectiveness of numerical simulations to model real life vibroflotation is ascertained. Parametric analysis for different granular materials and machine parameters is performed. The results of the extensive studies are used to identify parameters which can act as markers during the compaction process. These identified parameters are used to develop on-line compaction control tools, which can eventually lead to more efficient and cost effective compaction process. Liquefaction mitigation potential of the vibroflotation method is analysed in a numerical framework, which is validated against centrifuge results. Numerical simulation of loose saturated sands under seismic loading is investigated. The improvement in the liquefaction potential of granular soils subjected to vibroflotation is studied.

Project relevant publications

  • Nagula Sinduri S. (2021): Optimization of deep vibratory compaction as liquefaction mitigation measure. PhD thesis. Technische Universität Hamburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 50
  • Nagula Sinduri S. und J. Grabe (2020): Coupled Eulerian Lagrangian based numerical modelling of vibro-compaction with model vibrator. In: Computers and Geotechnics 123, No. 103545, DOI: 10.1016/j.compgeo.2020.103545
  • S. Nagula, J. Grabe und T. Bahl (2019): Numerical simulation of vibrocompaction based on CEL approach. In: Proceedings of 17th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE) 2019 in Reykjavik/Island, International Society for Soil Mechanics and Geotechnical Engineering, H. Sigursteinsson and others (eds.), pp. 1021–1026, DOI: 10.32075/17ECSMGE-2019-1021
  • Chmelnizkij A., Nagula S. and J. Grabe (2019): Numerical simulation of dynamic compaction in Abaqus/CEL and MPM. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 35, pp. 215–220, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Nagula S. and J. Grabe (2018): Installation effect of geosynthetic encased stone columns on existing columns. In: Proceedings of 11th International Conference in Geosynthetics 2018 in Seoul/Korea, International Geosynthetics Society
  • Nagula S. and J. Grabe (2018): First step to model the installation effect of geosynthetic encased sand columns on existing columns. In: Proceedings of Indian Geotechnical Conference (ICG) 2018 in Bangaluru/India
  • Nagula S. and J. Grabe (2018): Effectiveness of ground improvement in sands upon seismic loading using non-linear model. In: Proceedings of 5th Geotechnical Earthquake Engineering and Soil Dynamics Conference (GEESD) 2018 in Austin/USA, American Society of Civil Engineers, S.J. Brandenberg and M.T. Manzari (eds.), pp. 133–141
  • S. Nagula, P. Mayanja and J. Grabe (2018): Deep vibration compaction of sand using mini vibrator. In: Proceedings of 9th International Conference on Physical Modelling in Geotechnics (ICPMG) in London/UK, A. McNamara et al. (eds.), CRC Press, pp. 1229
  • Nagula S., Nguyen D.M. and J. Grabe (2018): Numerical modelling and validation of geosynthetic encased colums in soft soils with installation effect. In: Geotextiles and Geomembranes 46(6):790–800, DOI: https://doi.org/10.1016/j.geotexmem.2018.07.011
  • Chmelnizkij A., Nagula S. and J. Grabe (2017): Numerical simulation of deep vibration compaction in Abaqus/CEL and MPM. In Proceedings of 1st International Conference on the Material Point Method 2017 in Delft/The Netherlands, Elesevier Procedia, Series on Procedia Engineering Vol. 175, A. Rohe et al. (eds.), pp. 302–309
  • Nagula S. and J. Grabe (2017): 2-phase dynamic simulation of deep sand compaction to reduce liquefaction. In: Proceedings of 10th International Conference on Structural Dynamics (EURODYN) 2017 in Rome/Italy, Elsevier Procedia, Series on Procedia Engineering Vol. 199, F. Vestroni et al. (eds.), pp. 2396–2401
  • Nagula S. and J. Grabe (2017): Determination of intergranular strain parameters and their dependence on properties of grain assemblies. In: Proceedings of International Workshop on Advances in Laboratory Testing and Modelling of Soils and Shales (ATMSS) 2017 in Villars-sur-Ollon/Switzerland, A. Ferrari and L. Laloui (eds.), Springer Series in Geomechanics and Geoengineering, pp. 395–404
  • Grabe J., Zobel D., Nagula S. und A. Chmelnizkij (2017): Zur numerischen Modellierung von dynamischen Randwertproblemen. In: BAWMitteilungen Nr. 101 "Natürliche, künstliche und virtuelle Stoffe in der Geotechnik", S. 59–72, Bundesanstalt für Wasserbau

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Multiscale modelling of physical processes at soil-water interface

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG) and Österreichischer Wissenschaftsfonds (FWF), collaborative project GR 1024/22-1 dnd 22-2 (DFG) as well as i2257-N29 (FWF) in the framework of the D-A-CH agreement
  • Research partner: Dr. Christoph Goniva, DCS Computing, Linz, Austria
  • Duration: 01.07.2016 to 31.07.2020 (48 months)
  • Staff: Manuela Kanitz
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 48)

Project description

As part of the first project phase, physical processes at the free water-soil interface were investigated. These included mechanically and hydrodynamically induced erosion, transport and sedimentation processes. The focus was on underwater embankments made of sand, where such processes occur as a result of natural processes (tidal currents, surface waves, earthquakes, etc.) and construction-related processes (e.g. construction of artificial underwater embankments using underwater mining techniques). The corresponding effects on the stress state in underwater sand embankments and the associated embankment stability can be qualitatively categorised from a soil mechanics perspective, but a design model for the maximum long-term inclination of underwater sand embankments does not exist. Such a design model was developed based on a numerical model and accompanying model tests. The basis for this is a multi-scale model consisting of a continuum model including Navier-Stokes equations for the incompressible, viscous pore fluid and the surface water (solution of the field equations within the framework of CFD), a particle model including Newton's equations of motion for the grain structure (solution of the equations of motion within the framework of DEM) and a CFD-DEM coupling taking into account the interaction between the flowing fluid and the particles (flow resistance force, hydrodynamic buoyancy force, etc.).

Following theoretical preliminary work on fluid-particle coupling and CFD-DEM coupling, the latter was initially used to simulate the stability of small-scale underwater sand embankments as a result of various mechanical and hydrodynamic effects. In a second stage, an underwater sand slope with a height of approx. 5 metres was simulated at full scale. For this purpose, an intelligent "coarse graining" was applied within the framework of the CFD-DEM coupling, whereby the grain diameter of a sand was artificially increased so that larger areas can also be simulated with the CFD-DEM coupling. Finally, the resulting short and long-term inclination of underwater sand embankments was determined for various mechanical and hydrodynamic scenarios in order to derive a design model for artificially created underwater sand embankments.

The focus of the second project phase was on the expansion and development of the numerical method used to describe flow processes in soils. In this context, internal erosion (suffusion) in sandy soils was investigated first. Since the flow around the individual soil particles cannot be modelled in the non-resolved CFD-DEM, the method must be extended to capture the exact time and movement of the soil particles as the hydraulic gradient changes. The second focus of the continuation application was on the description of the water-air interface in the soil and the resulting capillary forces. New force models were developed and implemented for modelling the water-air interface in the soil using non-resolved CFD-DEM. These extensions enable deeper insights into the failure mechanisms of soil bodies and the modelling of water-soil interactions in saturated soils, as well as the first numerical calculation of partially saturated sandy slopes using non-resolved CFD-DEM.

Project relevant publications

  • Kanitz M. (2020): Experimental and numerical investigation of particle-fluid systems in geotechnical engineering. Dissertation. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 48
  • Kanitz M. und J. Grabe (2019): Gekoppelte CFD-DEM-Simulation zum Verflüssigungsverhalten gesättigter Sande. In: Tagungband zum BAW-Kolloquium Numerik in der Geotechnik 2019 in Karlsruhe, Bundesanstalt für Wasserbau, S. 31–36
  • Kanitz M. und J. Grabe (2019): Influence of suction dredging on the failure mechanism of sandy submarine slopes. In: Proceedings of 38th International Conferehnce on Ocean, Offshore and Artic Engineering (OMAE) 2019 in Glasgow/Scotland, electronically published, paper No. OMAE2019-95151, URL: Link
  • Kanitz M., Hager A., Grabe J. and C. Goniva (2019): Numerical and experimental analysis of the extraction mechanism of an anchor plate embedded in saturated sand. In: Computers and Geotechnics 111, pp. 191–201, DOI: 10.1016/j.compgeo.2019.03.014
  • Kanitz M. and J. Grabe (2019): Multiscale investigation of suffusion with coupled CFD-DEM. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 20, pp. 122–128, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Kanitz M. and J. Grabe (2018): Experimental study of the influence of the pore water pressure evolution and the shear band formation on the extraction resistance of submerged anchor plates. In: Proceedings of 37th International Conference on Ocean, Offshore & Artic Engineering (OMAE) 2018 in Madrid/Spain, published under No. OMAE2018-78306
  • Kanitz M. and J. Grabe (2018): Multiscale investigations on the failure mechanisms of submarine sand slopes with coupled CFD-DEM. In: Proceedings of 9th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE) in Porto/Portugal, Vol. 2, pp. 1485–1492, CRC Press, Taylor & Francis Group, ed. by A.S. Cardose et al.
  • Kanitz M., Denecke E. and J. Grabe (2018): Numerical investigations on the liquid-solid transition of a soil bed with coupled CFD-DEM. In: Proceedings of 9th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE) in Porto/Portugal, Vol. 1, pp. 367–374, CRC Press, Taylor & Francis Group, ed. by A.S. Cardose et al.
  • Kanitz M., Grabe J., Hager A., Goniva C. und C. Kloss (2017): "Numerical investigations of the extraction of submerged foundations by coupled CFD-DEM". In: Proceedings of International Conference on Ocean Offshore & Artic Engineering (OMAE) 2017 in Trondheim/Norway, electronically published under OMAE2017-61299
  • Kanitz M., Grabe J., Hager A. Goniva C. und C. Kloss (2017): Extraction mechanism of an anchor plate - simulation with coupled CFD-DEM. In: Proceedings of Conference on Maritime Energy (COME) 2017 in Hamburg/Germany, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der TU Hamburg, Heft 38, S. 231–249

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Optimised design of combined sheet pile walls for installation and final states

Status: 26.11.2024
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General data

  • Funding: Forschungsvereinigung Stahlanwendung e. V. (FOSTA), Förderkennzeichen: P 1327
  • Project management: Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke e. V.“ (AiF), Förderkennzeichen: IGF 19937
  • Project partner: Prof. Dr.-Ing. Ulrike Kuhlmann, Institut für Konstruktion und Entwurf, Universität Stuttgart, Germany
  • Duration: 01.06.2018 bis 31.01.2021 (30 months)
  • Staff: Jannik Beuße
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 59)

Project description

The development of ship sizes is accompanied by special requirements for the quay walls of harbour facilities. As part of this research project, investigations were carried out to improve the economic efficiency and safety of the dimensioning of combined sheet pile walls for the installation and final state. The stresses on the profile during installation have so far only been included in the profile selection as empirical experience. Investigations into this were intended to provide holistic design criteria for optimized profile selection in order to ensure not only cost-effectiveness but also damage-free installation of the profiles in the correct position. As part of the design of the final state, the potential of the bearing piles of combined sheet pile walls remains unutilised with regard to the base bedding approach and the partial welding of double bearing piles. Building on the predecessor project P813, the economic efficiency is to be improved. In addition, the compatibility of the design with the changes to lateral-torsional buckling adopted in EN 1993-1-1 is to be ensured, and the installation situation improved through more economical regulations in EN 1993-5. For the design of intermediate piles, the consistency of the existing Annex C in EN 1993-5 and the concept of partially plastic moment resistance adopted for EN 1993-1-1 is to be ensured by means of an investigation. EN 1993-5, EAU 2012 and the predecessor project already provide approaches for the design of combined steel sheet piles that have been optimized in terms of their cost-effectiveness and application safety. Despite the improvements that have been made, the potential for greater cost-effectiveness and application safety remains unutilised. The same applies to the simplicity and therefore applicability of the rules. The aim of this project is to utilize this potential and thus provide SMEs with considerable benefits in terms of cost-effectiveness and safety when using combined steel sheet piling.

Project relevant publications

  • Beuße J. (2023): Zur Einbringung und zum Tragverhalten von kombinierten Spundwänden von Ufereinfassungen. Dissertation. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 59
  • Beuße J. und J. Grabe (2020): Messtechnische Begleitung der Einbringung einer Tragbohle mittels Vibration und Schlagrammung. In: Geotechnik 43(2):61–76, DOI: 10.1002/gete.201900024
  • Beuße J. und J. Grabe (2020): Zum Messen der Bewegungen und Verformungen einer Tragbohle im Zuge einer schweren Rammung: In: Tagungsband zum Workshop Messen in der Geotechnik 2020 in Braunschweig, Mitteilung des Instituts für Geomechanik und Geotechnik der TU Braunschweig, Heft 110, S. 325–334
  • Beuße J. und L. Vollmert (2019): Simulationsansätze zur Modellierung geogitterbewehrter Tragschichten unter statischer und dynamischer Belastung. In: Tagungsband zur Fachsektionstagung Geotechnik 2019 in Würzburg, Deutsche Gesellschaft für Geotechnik e. V. (Hrsg.), S. 530
  • Beuße J., Grabe J., Kuhlmann U. und A. Enders (2019): Optimierte Auslegung von kombinierten Stahlspundwänden für den Einbringvorgang und den Endzustand. In: Tagungsband zum Fachseminar Stahl im Wasserbau 2019 in Braunschweig, Mitteilung des Instituts für Grundbau und Bodenmechanik der Technischen Universität Braunschweig, Heft 109, S. 169–190

Project relevant student works

  • Alkateeb D. (2019): Untersuchung der Änderung der Bodenzustandsgrößen in Abhängigkeit der Rammführung während der Einbringung von Tragbohlen. Master thesis
  • D., A. (2019): Untersuchung des Schwingverhaltens einer schweren Tragbohle während der Einbringung. Bachelor thesis
  • N., Q. (2019): Ermittlung von Drehbettungsansätzen für Tragbohlen kombinierter Spundwände im Klei. Master thesis
  • H., J. (2019): Untersuchung der dynamischen Einflüsse des Einbringverfahrens von Tragbohlen kombinierter Spundwände. Master thesis

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Mechanical-hydraulic interaction in porous asphalt considering unsaturated states

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), collaborative project GR 1024/25-1 and 25-2 as well as OE 514/4-1 and 4-2
  • Project partner: Prof. Dr.-Ing. habil. Markus Oeser, Lehrstuhl und Institut für Straßenwesen, RWTH Aachen, Germany
  • Duration: 2016 to 2020 (48 months)
  • Staff: Tom Törzs
  • Status: Completed project, final report, PhD thesis published in institute's series (Vol. 55)

Keywords

Unsaturated soils, capillarity

Project description

As part of the joint research project, the system behaviour of infiltration-capable pavements with a polyurethane-bound surface layer on partially saturated base layers and natural soils is being investigated. There is a hydraulic-mechanical interaction between the surface course and the underlying layers and soils, which is being investigated experimentally and numerically as part of the project.

The primary aim of the research project is to create a basis for the design of water-permeable road structures. The effects of partial saturation on the stress-strain behaviour of the individual layers of the structure are to be quantified and taken into account. Furthermore, it is to be shown that the use of polyurethane (PU) as an alternative binder can significantly improve the fatigue resistance and service life of bound surface courses. In order to fulfil the objectives, fundamental experimental investigations were carried out in the first project phase on both the mechanical and hydraulic material behaviour on a laboratory, model scale and field scale. The results of these investigations will be used in the second phase of the project to calibrate hydraulic and mechanical material laws. These will in turn be used in numerical investigations into the load-bearing behaviour of water-permeable road structures in order to simulate the hydraulic-mechanical coupled behaviour of the system under wheel load as realistically as possible. Recommendations for optimized hydraulic and mechanical system behaviour of permeable road cross-sections are to be derived from the simulation results.

In addition, in-depth experimental investigations were carried out: On the one hand, studies on the pore space of the porous surface layer were performed using imaging methods and possible factors that impair the drainage performance are to be identified. Secondly, load tests were carried out again using the MLS30 mobile load simulator in order to assess the influence of high overruns on the system and the PU-bound surface layer in particular.

Project relevant publications

  • Törzs T. (2022): Zum hydraulisch-mechanisch gekoppelten Verhalten teilgesättigter granularer Geomaterialien infolge hydraulischer und mechanischer Beanspruchungen. PhD thesis. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 55
  • Lu G., Wang H., Törzs T., Liu P., Zhang Y., Wang D., Oeser M. and J. Grabe (2020): In-situ and numerical investigation on the dynamic response of unbounded granular material in permeable pavement. In: Transportation Geotechnics, DOI: https://doi.org/10.1016/j.trgeo.2020.100396
  • Stark A., Törzs T. und J. Grabe (2020): Permissible spatial variation of CCC data from driving comfort requirements over time. In: Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, DOI: 10.1680/jgeen.19.00195
  • Lu G., Törzs T., Liu P., Zhang Z., Wand D., Oeser M. and J. Grabe (2020): Dynamic response of fully permeable pavements: development of pore pressures under different modes of loading. In: Journal of Materials in Civil Engineering 32(7), DOI: 10.1061/(ASCE)MT.1943-5533.0003217
  • G. Lu, P. Liu, T. Törzs, D. Wang, M. Oeser, J. Grabe (2020): Numerical analysis for the influence of saturation on the base course of permeable pavement with a novel polyurethane binder. In: Construction and Building Materials 240(2020) 117930, DOI: 10.1016/j.conbuildmat.2019.117930
  • Törzs T., Grabe J., Lu G. und M. Oeser (2019): Investigations on microstructure characteristics of porous pavement based on X-ray CT scanning. In: Proceedings of 7th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT) 2019 in Nagoya (Japan), Vol. 7, No. 2, pp. 609-614, URL: https://www.jstage.jst.go.jp/article/jgssp/7/2/7_v07.094/_pdf/, DOI: 10.3208/jgssp.v07.094
  • Milatz M., Törzs T. und J. Grabe (2019): Zur Untersuchung mikroskopischer Strukturen und Prozesse in porösen Medien mittels Mikro-Computertomografie. In: Tagungsband zur Fachsektionstagung Geotechnik 2019 in Würzburg, Deutsche Gesellschaft für Geotechnik e. V. (Hrsg.), S. 378
  • Törzs T., Lu G., Monteiro A.O., Wand D., Grabe J. and M. Oeser (2019): Hydraulic properties of polyurethane-bound permeable pavement materials considering unsaturated flow. In: Construction and Building Materials 212:422-430, DOI: 10.1016/j.conbuildmat.2019.03.201
  • Milatz M., Törzs T., Nikooee E., S.M. Hassanizadeh und J. Grabe (2018): Theoretical and experimental investigations on the role of transient effects in the water retention behaviour of unsaturated granular soils. In: Geomechanics for Energy and the Environment 15:54-64. DOI: 10.1016/j.gete.2018.02.003
  • Törzs T., Grabe J., Lu G. and M. Oeser (2018): Investigation of the water-retention behaviour of water-permeable pavement materials based on innovative binder materials. In: Proceedings of 7th International Conference on Unsaturated Soils (UNSAT2018) in Hongkong, C.W.W. Ng et al. (eds), URL: http://gcf-conf.ust.hk/unsat2018/paper/pdf/2-25.UNSAT2018_369.pdf
  • Milatz M., Törzs T. and J. Grabe (2018): Investigation on the transient effects on the soil-water characteristic curve of different granular soils. In: Proceedings of 7th International Conference on Unsaturated Soils (UNSAT2018) in Hongkong, C.W.W. Ng et al. (eds), Vol. 1, pp. 355-360, URL: http://gcf-conf.ust.hk/unsat2018/paper/pdf/1b-6.UNSAT2018_038.pdf
  • Milatz M., Törzs T. und J. Grabe (2016): Settlements in unsaturated granular soils induced by changes in saturation and suction. In: Proceedings of 3rd European Conference on Unsaturated Soils 2016 in Paris/France, No. 14009

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Wave propagation and shock front formation for high-energy impacts in saturated soils

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), projects GR 1024/29-1 and 29-2
  • Duration: 2016 to 2020 (48 months)
  • Staff: Alexander Chmelnizkij
  • Status: Completed project, DFG final report, PhD thesis published in institute's series (Vol. 57)

Keywords

Soil dynamics, wave propagation, shock formation, saturated soil, poromechanics, Material Point Method (MPM)

Project description

As part of the research project, the propagation of waves caused by impulse-like loads in saturated soils is being investigated. For this purpose, measurements have already been carried out in-situ during dynamic intensive compaction measures and soil blasting. The results of these measurements are used for validation purposes for numerical simulations. The simulations are carried out using two numerical methods, the Finite Element Method (FEM) and the Material Point Method (MPM). These methods were compared and insights into their applicability were gained. Furthermore, two different mathematical models and governing equations for the saturated soil, the u-p and v-w formulations, were analysed for their differences in the simulation of highly dynamic processes. The influence of pore water and the discontinuity of the solution resulting from the non-linearity of the hypoplastic material model on wave propagation is investigated.

Project relevant publications

  • Chmelnizkij A. (2023): Regularized MPM for porous media. PhD thesis. Technische Universität Hamburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 57
  • Chmelnizkij A. und J. Grabe (2019): Dynamic compaction. In: The Material Point Method in geotechnical engineering: a practical guide, J. Fern, A. Rohe, K. Soga and E Alonso (eds.), chapter 19, pp. 325–339, URL Link
  • Chmelnizkij A. und J. Grabe (2019): Different formulations and integration schemes. In: The Material Point Method in geotechnical engineering: a practical guide, J. Fern, A. Rohe, K. Soga and E Alonso (eds.), chapter 3, pp. 57–66, URL Link
  • Chmelnizkij A., F. Ceccato, Grabe J. and P. Simonini (2019): 1D wave propagation in saturated soils: verification of two-phase MPM. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 36, pp. 221–228, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Chmelnizkij A., Nagula S. and J. Grabe (2019): Numerical simulation of dynamic compaction in Abaqus/CEL and MPM. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 35, pp. 215–220, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Coelho B.Z., Chmelnizkij A. and J. Grabe (2019): Geometric and material non-linear wave propagation with the MPM. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 33, pp. 201–207, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Stapelfeldt M., Chmelnizkij A. and J. Grabe (2019): Numerical investigations on bearing capacity analyses of shallow foundations in small and large deformation. In: Proceedings of 2nd International Conference on the Material Point Method for Soil-Water-Structure Interaction 2019 in Cambridge/UK, paper No. 19, pp. 115–121, URL http://mpm2019.eu/papers, ISBN: 978-7-7521-0316-1
  • Chmelnizkij A., Nagula S. and J. Grabe (2017): Numerical simulation of deep vibration compaction in Abaqus/CEL and MPM. In Proceedings of 1st International Conference on the Material Point Method 2017 in Delft/The Netherlands, Elesevier Procedia, Series on Procedia Engineering Vol. 175, A. Rohe et al. (eds.), pp. 302–309
  • Heins E., Seitz K.-F., Chmelnizkij A. und J. Grabe (2017): Advances in Numerical Modelling of Different Ground Improvement Techniques. In: Geotechnical Engineering Journal of SEAGS & AGSSEA 48(3), published online
  • Grabe J., Zobel D., Nagula S. und A. Chmelnizkij (2017): Zur numerischen Modellierung von dynamischen Randwertproblemen. In: BAWMitteilungen Nr. 101 "Natürliche, künstliche und virtuelle Stoffe in der Geotechnik", S. 59–72, Bundesanstalt für Wasserbau
  • Chmelnizkij A. und J. Grabe (2016): Untersuchungen zur Wellenausbreitung im Boden infolge impulsartiger Beanspruchungen aus Fallmassen und Explosionen. Tagungsband zum 12. Hans Lorenz-Symposium 2016 in Berlin, Veröffentlichungen des Grundbauinstituts der TU Berlin, Heft 70, S. 137–148
  • J. Kirstein, J. Grabe und A. Chmelnizkij (2016): Numerische Berechnungen und messtechnische Begleitung zur Dynamischen Intensivverdichtung. In: Tagungsband zur 34. Baugrundtagung 2016 in Bielefeld, S. 297–304
  • Grabe J., Hamann T. und Chmelnizkij A. (2014): Numerical simulation of wave propagation in fully saturated soil modelled as a two-phase material. Proceedings of 9th International Conference on Structural Dynamics (Eurodyn) 2014 in Porto/Portugal, pp.631–63

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Nautical depth in harbour beds with fluid mud

Status: 26.11.2024
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General data

  • Customer: Hamburg Port Authority (HPA)
  • Duration: 01.09.2018 to 30.09.2022 (Nguyen), cost neutral extension 01.10.2022 to 28.02.2023 (Stanford, Somasundaram)
  • Staff: Duc Michael Nguyen, Dr.-Ing. Hans Stanford, Rahul Somasundaram
  • Status: Completed projects, internal report

Keywords

Fluid mud, rheology, non-Newtonian fluid, rheometer, oedometer test, ship-fluid mud interaction, Smoothed Particle Hydrodynamics (SPH)

Project description

The global increase in freight transport via waterways means that ships are also getting bigger and bigger. This poses a particular challenge for harbours such as Hamburg, whose maximum draught depends on the tide and geographical location. The nautical depth is a measure of the navigability of a harbour. This is a nautically safe horizon up to which ships can submerge without their manoeuvrability being impaired. In recent years, sediment echo sounding measurements in the mooring basins have shown that a fluid mud layer forms above the solid harbour floor. The nautical depth is currently above this fluid mud layer. In the course of water depth maintenance and fairway adjustment, there are now plans to allow seagoing vessels to immerse themselves in the fluid mud of a mooring basin for a limited period of time. The prerequisite: maintaining the Archimedean principle of the ship's hull. Releasing the fluid mud for shipping is associated with enormous cost savings in terms of sediment management, as the corresponding water depths are not made possible by dredging the sediments, but by utilizing the fluid mud. In addition to the potential financial benefits, the ecological relief resulting from the reduced maintenance measures must also be taken into account.

   

Figure: Vertical penetration of a ship into the fluid mud in a basin due to the tide


In cooperation with the Hamburg Port Authority (HPA) in the joint project Nautical Depth, a possible navigability in fluid mud in mooring tubs of the Port of Hamburg was investigated. The following aspects were investigated and analysed:

  • Rheological behaviour of fluid mud: Using a rheometer, the non-Newtonian flow behaviour of the fluid mud is first investigated as a function of various input parameters (density, organics content, mineralogy). On this basis, a rheological model for the fluid mud was derived, which approximates the viscoelastic behaviour. 
  • Sedimentation and consolidation behaviour of fluid mud: In the course of the project, a new type of column oedometer was developed and built, with which it is possible to determine effective stress σ' during the sedimentation and consolidation processes under different boundary conditions (e.g. different pressure levels, oedometric boundary conditions). The results obtained from this should ultimately clarify whether consolidated sediment forms as a result of the submersion of a ship's hull. 
  • Numerical simulation of ship-fluid mud interaction due to tide: In the final step, conventional analyses and numerical simulations based on the Smoothed Particle Hydrodynamics (SPH) were carried out. The aim was to simulate various immersion scenarios in the Port of Hamburg in order to rule out the worst case (loss of manoeuvrability and buoyancy).

Project relevant student works

  • Menger, A. (2020): Zum Sedimentations- und Konsolidationsverhalten von Fluid Mud unter ödometrischer Kompression. Bachelor thesis
  • Ortmüller, L. (2019): Experimentelle Untersuchung zur Genese mariner Sedimente. Bachelor thesis
  • Katt, J. (2018): Zur Rheologie von Fluid Mud. Project work

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Hydraulic loosening of soils

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 01.09.2018 bis 31.08.2022 (12 months)
  • Staff: Rahul Somasundaram
  • Status: Completed project, successor DFG project GR 1024/43-1

Project description

As part of previous projects, the hydraulic loosening of the soil (e.g. jet grouting process with a fluid jet) was investigated using physical modelling (1g model tests) and numerical simulation based on the Smoothed Particle Hydrodynamics (SPH). For this purpose, the SPH codes GADGET and GADGET-H2O were further developed and named GADGET-Soil. It is based on a dynamic two-phase model for saturated soil. The current project is focussing on the following extensions of this SPH code:

  • Modelling of transition from the saturated to a suspension and vice versa.
  • More advanced simulation of the nozzle jet process than before (increasing the spatial resolution of the fluid jet, implementation of the particle splitting technique, implementation of a turbulence model).
  • Use of CPU-based parallelization based on MPI.

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Numerical recalculation of quay walls and their repair

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 01.02.2019 to 31.01.2023 (48 months)
  • Staff: Paul Vogel
  • Status: Completed project

Project description

The Port of Hamburg has quay walls with a total length of approx. 43 km. The Hamburg Port Authority (HPA) is currently having approx. 36 km of these analysed for their stability, as changes to the existing statics, some of which are several decades old, or damage can impair stability. For this reason, the HPA has published a recalculation guideline (similar to the recalculation guideline for bridges), which specifies the procedure for recalculation. If conventional calculation methods are not sufficient to ensure adequate stability, scientific methods such as monitoring or numerical methods like the Finite Element Method (FEM) can be used. However, the following questions remain unanswered when using the FEM for recalculation:

  • How does the degree of discretization influences the load-bearing capacity and the safety of a quay wall?
  • How can the conventional design methods in EC7 be harmonized with the FEM?
  • If the quay wall cannot be verified using FEM, how can various repair measures be used to ensure sufficient stability?

Project relevant publications

  • Vogel P., Struve A. und J. Grabe (2023): Zur numerischen Zustandsbeurteilung von Bestandskaimauern. In: Tagungsband zum 37. Christian Veder Kolloquium 2023 in Graz/Österreich, Veröffentlichungen des Instituts für Bodenmechanik, Grundbau und Numerische Geotechnik  (NAWI Graz Geozentrum), Heft 16, S, 133–148
  • Vogel P. (2022): Zur Anwendbarkeit von embedded piles bei der Modellierung von Kaimauern. In Tagungsband zur 27. Baugrundtagung 2022 in Wiesbaden - Beiträge der Spezialsitzung für junge Geotechnik-Ingenieure und -Ingenieurinnen, Deutsche Gesellschaft für Geotechnik (Hrsg.), S. 91–100, URL https://www.dggt.de/images/bgt2022-s01.pdf

  • Vogel P., Grabe J., Jürgens H. und S. Henke (2022): Zur numerischen Bemessung geotechnischer Bauwerke gemäß EC 7. In: Tagungsband zum 28. Darmstädter Geotechnik-Kolloquium 2022, Mitteilungen des Institutes für Geotechnik der Technischen Universität Darmstadt, Heft 113, DOI 10.26083/tuprints-00021134, URL https://tuprints.ulb.tu-darmstadt.de/21134

  • Jürgens H., Vogel P., Henke S., Grabe J. (2022): Zur numerischen Berechnung der globalen Standsicherheit von Bauwerken im Boden. In: Geotechnik 45(3), S. 155–169, DOI 10.1002/gete.202200003
  • Vogel P., Grabe J. und F. Feindt (2021): Finite-Elemente-Analyse zur Standsicherheit einer Bestandskaimauer und zu den Auswirkungen von Ertüchtigungsmaßnahmen. In: Bauingenieur 96(12):427–440

Project relevant student works

  • Cortez A. (2020): Numerische Untersuchung zum Einfluss des Diskretisierungsgrads bei der Nachrechnung von Bestandskaimauern. Project work
  • Struve A. (2020): Vergleich verschiedener Verfahren zur Bemessung einer Kaimauer im Grenzzustand der Tragfähigkeit mittels FEM. Bachelor thesis
  • Reimer L. M. (2019): Zustandsbewertung und Sanierungskonzept verschiedener Bestandskaimauern im Hamburger Hafen. Master thesis

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Investigation of hysteretic capillary pressure-saturation behaviour of unsaturated soils by means of Computed Tomography and numerical methods

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 2462 “Processes in natural and technical particle-fluid systems (PintPFS)”, postdoc position
  • Duration: 01.03.2019 to 28.02.2024
  • Staff: Dr.-Ing. Marius Milatz
  • Status: Completed project, habilitation published in institute's series (Vol. 56)

Project description

The water retention behaviour, described by the capillary pressure-saturation relationship, plays a key role in the description of the hydraulic and mechanical behaviour of partially saturated soils and is therefore crucial for the soil mechanical understanding of capillary effects. Partial saturation influences the hydraulic conductivity of soils and leads to capillary cohesion due to suction stresses or capillary pressure and the surface tension of the pore water, which increases the shear strength of unsaturated granular soils.

Imaging techniques such as Computed Tomography (CT) are used in research to gain insights into the behaviour of unsaturated granular soils at the grain-to-grain level. For this purpose, various laboratory tests and in-situ experiments are carried out in CT scanners, see Figure 1 and 2. The three-dimensional CT data obtained from soil mechanical processes, such as shearing or cyclic dewatering and irrigation, allows a better understanding of the macroscopic soil behaviour through insights into the microscopic behaviour of the unsaturated grain skeleton. Its particles are held together by water clusters or capillary bridges.

 

Figure 1: Reconstructed and segmented CT data of uniaxial compression test of unsaturated sand. Top: sand and water, bottom: Water phase. Water clusters and capillary bridges hold the grains together during shearing

 

Figure 2: Greyscale images (vertical section) from CT scans during the dewatering of sand in an experiment to measure the hysteretic water retention curve — sand grains (light grey), water-filled pores (grey), and air-filled pores (black)

 

Experimental data from CT experiments can also be used to validate and improve numerical methods that can be used to simulate capillary effects. For example, the Discrete Element Method (DEM) with capillary bridge models and the Multiphase Lattice Boltzmann Method (LBM) can be used to model the behaviour of partially saturated granular soils. The latter method makes it possible to simulate the hydraulic-mechanical behaviour of multiphase fluid mixtures in porous media, taking into account the surface tension in the micro-model. LBM-DEM coupling is also possible.

Project relevant publications

  • Milatz M. (2022): Investigation of capillary effects on the grain scale by means of in situ experiments, imaging and numerical simulations. Habilitation. Technische Universität Hamburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 56, DOI: 10.15480/882.4803
  • Milatz, M. and J. Grabe (2019): Microscopic investigation of the hydro-mechanical behavior of unsaturated granular media with X-ray CT. In: Proceedings of 7th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT) 2019 in Nagoya/Japan. Weblink (open access)
  • Milatz, M., Törzs, T. and J. Grabe (2019): Zur Untersuchung mikroskopischer Strukturen und Prozesse in porösen Medien mittels Mikro-Computertomografie. In: Tagungsband zur Fachsektionstagung Geotechnik 2019 in Würzburg, Deutsche Gesellschaft für Geotechnik e. V. (Hrsg.), S. 378-383. Link
  • Milatz, M., Andò, E., Helfen, L., Hüsener, N. and A. Tengattini (2019): Partial saturation in granular media. Repositoty of CT data at Institut Laue-Langevin (ILL). DOI: 10.5291/ILL-DATA.UGA-73.
  • Milatz, M. (2020): An automated testing device for continuous measurement of the hysteretic water retention curve of granular media. In: Acta Geotechnica. DOI: 10.1007/s11440-020-00922-y.
  • Milatz, M. (2020): Application of single-board computers in experimental research on unsaturated soils. In: Proceedings of 4th European Conference on Unsaturated Soils (E-UNSAT) 2020 in Lisboa/Portugal, R. Cardoso et al. (eds.), DOI: 10.1051/e3sconf/202019502022
  • Milatz M., Hüsener N., Ando E., Viggiani G. and J. Grabe (2021): Quantitative 3D imaging of partially saturated granular materials under uniaxial compression. In: Acta Geotechnica, DOI: 10.1007/s11440-021-01315-5
  • Milatz M., Hüsener N., Ando E., Viggiani G. and J. Grabe (2021): Data from in situ uniaxial compression experiments on unsaturated granular media with X-ray CT-imaging. Repository of CT data at TUHH Open Research (TORE), Hamburg University of Technology, DOI: 10.15480/336.3291
  • Hüsener N., Helfen L., Milatz M. and Tengattini, A. (2021): Combined X-ray- and neutron-tomography imaging of capillary collapse in unsaturated granular soils. Repository of data at Institut Laue-Langevin (ILL). DOI: 10.5291/ILL-DATA.1-05-53
  • Milatz M., Ando E. and G. Viggiani (2022): Data from in situ X-ray CT imaging of transient water retention experiments with cyclic drainage and imbibition. TUHH Open Research (TORE), Hamburg University of Technology, DOI: 10.15480/336.4291
  • Milatz M. (2022): Implementation of a multiphase Lattice Boltzmann Method for the simulation of water retention behaviour of CT scanned granular media. TUHH Open Research (TORE), Hamburg University of Technology, DOI: 10.15480/336.4364
  • Milatz M. (2022): Zur Simulation von Kapillareffekten in granularen Böden mit der Mehrphasen-Lattice-Boltzmann-Methode. In: Tagungsband zum Workshop "Numerische Methoden in der Geotechnik", Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg, Heft 53, S. 9–25.
  • Milatz, M., Andò E., Viggiani G., Mora S. (2022): In situ X-ray CT imaging of transient water retention experiments with cyclic drainage and imbibition. In: Open Geomechanics 3, DOI: 10.5802/ogeo.13

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Capillary collapse in unsaturated soils

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 2462 “Processes in natural and technical particle-fluid systems (PintPFS)”
  • Duration: 16.05.2019 to 15.11.2022 (6 months + 6 months Corona-caused extension)
  • Staff: Nicole Hüsener
  • Status: Completed project

Keywords

Unsaturated soils, capillarity, capillary effects, capillary collapse, Computed Tomography (CT)

Project description

In unsaturated soils, the cohesion of the grain skeleton is significantly influenced by the so-called “capillary cohesion”. The surface forces of the pore water create suction, which press the individual soil grains together and thus lead, among other things, to an increased shear strength of the soil. The magnitude of the suction depends on the degree of saturation of the soil. Since the capillary cohesion disappears in both the dry and saturated state, this is also referred to as “apparent cohesion”. As a result of natural fluctuations in the water content or the degree of saturation of the soil, for example due to precipitation or a rising groundwater level, there is a risk of the grain skeleton losing its cohesion in the event of saturation due to the increasing dissolution of the capillary bridges. The sudden rearrangement of the grain skeleton that this entails is known as capillary collapse and, under certain conditions, can lead to very large settlements in the soil. Loosely deposited, fine-grained soils with a metastable structure are particularly at risk in this context. Although it was recognized early on that the microstructure plays a decisive role in the collapse process, due to a lack of adequate investigation methods, research has long focused on the macro level, so that the processes involved are still only inadequately understood. Newer methods such as Computed Tomography (CT) as an imaging technique allow insights into the microscopic processes and can thus contribute to a deeper understanding of the phenomenon.

 

Figure 1: Oedometer test

 

Objectives and work plan  After a soil mechanical characterization of the model soil, the collapse potential is to be estimated experimentally, for example with the aid of oedometer tests (see Figure 1). In order to gain a better understanding of the processes involved in capillary collapse at the micro level, miniaturized laboratory tests will be carried out using imaging techniques such as Computed Tomography (see Figure 2). The three-dimensional CT images obtained can be used to detect, visualize and subsequently analyse microscopic changes and particle movements during gradual saturation inside the sample. Of particular interest in this context are various possible influencing factors, such as the organic matter contained in the soil or the direction of irrigation. For comparison purposes, almost ideally round glass sphere packings with a grain size distribution modelled on the tipping floor are also being investigated. In future, the data obtained can serve as a basis for the development and validation of a numerical model for the simulation of capillarity.

 

Figure 2: Selected SEM and X-Ray CT scans

 

Project relevant publications

  • Hüsener N., Helfen L., Komodromos M., Milatz M., Tengattini A. and C.M. Toffoli (2023): Combined X-ray- and neutron-tomography investigation of capillary collapse in unsaturated granular soils subjected to loading. CT data repository, Institut Laue-Langevin (ILL) in Grenoble/France, DOI: 10.5291/ILL-DATA.1-07-11
  • Hüsener N. and J. Grabe (2023): Capillary collapse of unsaturated granular soils: experimental investigation and microscale insights. In: Proceedings of 8th International Conference on Unsaturated Soils 2023 in Milos/Greece, E3S Web of Conferences 382, No. 02004, DOI: 10.1051/e3sconf/202338202004
  • Hüsener, N. und Grabe, J. (2022): Experimental investigation of capillary collapse of partially saturated granular media. In: Tagungsband zur internationalen Konferenz „Processes in natural and technical Particle-Fluid-Systems (PintPFS)“ 2022 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 53, S. 109–120, DOI: 10.15480/882.4640
  • Hüsener, N., Helfen, L., Milatz, M. und Tengattini, A. (2021): Combined X-ray- and neutron-tomography imaging of capillary collapse in unsaturated granular soils. Data repository at Institut Laue-Langevin (ILL). DOI: 10.5291/ILL-DATA.1-05-53

Project relevant student works

  • Khosroshahli, M. (2022): Experimentelle Untersuchung der Auswirkungen einer Vorbelastung auf das Kollapsverhalten eines Kippenbodens. Bachelor thesis
  • Grube, L. (2021): Parameterstudie zum Kollapspotential eines Kippenbodens. Bachelor thesis
  • Henke, S. (2021): Experimentelle Untersuchung der Versickerung von Wasser in teilgesättigten Böden mittels Computertomografie. Bachelor thesis
  • Saif, M. (2021): Experimentelle Untersuchung des Wasserretentionsverhaltens eines Kippenbodens. Bachelor thesis
  • Kühnemund, T. (2020): Experimentelle Abschätzung des Kollapspotentials eines Kippenbodens bei inkrementeller Bewässerung. Bachelor thesis
  • Zeh, C. (2020): Möglichkeiten der numerischen Simulation des kapillaren Kollapses. Bachelor thesis
  • Karimi, P. (2020): Untersuchung von zu kapillarem Kollaps neigenden Böden mittels Computertomografie. Project work

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Development of an MRS system to prevent mobile construction machinery from tipping over on a deformable subsoil

Status: 26.11.2024
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General data

  • Funding: Bundesministerium für Wirtschaft und Klimaschutz (BMWK)

  • Project management: Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke“ e. V. (AiF), IGF-Vorhaben 20348 N

  • Duration: 01.11.2018 to 30.11.2021

  • Staff: Francisco Williams Riquer

  • Status: Completed project, AiF final report

Keywords

Mobile construction machine, deformable subsoil, field testing,

Project description

Due to the special mode of operation and centre of gravity of construction vehicles with tracked undercarriages, such as drilling rigs in special geotechnical  engineering, serious accidents caused by equipment overturns occur time and again, often resulting in considerable personal injury and property damage, for which, in addition to human error, subsoil subsidence is often responsible. As the construction industry is characterised by small and medium-sized companies that operate this type of equipment, the planned research project is highly relevant for the entire foundation engineering sector and in some cases even beyond.

As part of the research project with the co-operation partners Bauer Maschinenbau GmbH and Keller Geräte & Service GmbH, the risk of construction machinery with a high focus on tracked undercarriages overturning is to be investigated with the help of measurements and numerical simulations, with the overall aim of laying the foundations for a driving safety assistant based on a measurement-regulation-control system (MRS system). Such a system could detect an imminent overturn based on the movement behaviour of the construction vehicle, similar to the ESP system in motor vehicles known from the ‘moose test’, and trigger various safety measures. This would make it possible to avoid many serious accidents.

In the work programme of the research project, the movement behaviour of construction machinery with a high system centre of gravity is initially to be characterized using the example of special foundation engineering machinery, whereby movement patterns of an imminent equipment overturn are to be identified. These questions are investigated by numerical simulation of the vehicle kinematics and dynamics in combination with a compliant subsoil modelled by constitutive models. The numerical models to be developed are based on real vehicles and are to be validated by means of measurements on instrumented special civil engineering equipment from Bauer. This includes on suitable Keller construction sites and on the Bauer test site in Aresing. Furthermore, the numerical models allow various overturning scenarios to be investigated virtually without danger.

Based on the numerical models developed, and the field measurements carried out, the next step was to develop an MRS system based on computer simulations, in which algorithms for detecting and avoiding virtual device overturns are to be developed. If the prospects of success in the development of an MRS system based on computer simulations are good, a feasibility study on the transferability of the system to a prototype will be carried out. This step forms the basis for a planned follow-up research project in which the implementation of the MRS system in real construction vehicles could be tackled together with system tests.

 

Figure 1: Model of mobile construction machine and selected results for scenarios of its motion on a deformable subsoil

 

Figure 2: Selected results from field tests

Project relevant publication

  • Final report (see link), also available at Forschungskuratorium Maschinenbau (FKM) e. V., Lyoner Str. 18, 60528 Frankfurt am Main/Germany, e-mail: info@fkm-net.de, phone: +49 69 6603 1352

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Investigation of gas migration as a TRIggering mechanism for Submarine landslides on COntinetal slopes (TRISCO)

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), collaborative project No. GR 2014/35-1 and UR 226/3-1
  • Project partner: Prof. Dr. Morelia Urlaub, junior professor for Marine Geomechanics at GEOMAR, Kiel/Germany
  • Duration: 01.07.2019 to 30.09.2021 (27 months)
  • Staff: Pauline Kaminski
  • Status: Completed project, DFG final report, PhD thesis published in institute's series (Vol. 62)

Keywords

Gassy soils, shear strength, submarine slope, slope failure

Project description

The primary objective of the research project is to verify or falsify the hypothesis that landslides on continental submarine slopes are caused by the reduction of sediment shear strength due to gas bubbles and/or gas-induced excess pore water pressure, even in very shallow submarine slopes. Gas bubbles are formed as a result of changes in pressure and temperature after gases start to migrate through the sediment. The secondary objective of the project is to verify or falsify the hypothesis that multiple triggers are required for landslides in very shallow submarine slopes. The focus is on a combination of gas bubble reduction of sediment shear strength and earthquake effects up to micro-earthquakes with a magnitude of 2.0. The result of the research project will contribute to the current understanding of the triggering mechanism for landslides in continental shallow submarine slopes with far-reaching consequences. This includes improving the strategy for assessing corresponding submarine slope landslides and introducing strategies to mitigate the consequences. The results will also serve as a basis for recommendations on the stability assessment of subsea slopes in nearly saturated (gas-bearing) sediments. In particular, for planned gas hydrate production, a better understanding of the role of gas in slope stability is essential. If gas migration turns out to be a potential cause of subsea slope landslides, the hypothetical triggering mechanisms for many subsea slope landslides will need to be re-evaluated taking into account the impact of gas on slope stability. In addition, the results of this project will provide new insights into the controlling factors of upward gas migration in the subseafloor environment.

Project relevant publications

  • Kaminski P. (2024): Experimental investigations of the mechanics of gassy sands – testing methodology, shear tests, and imaging. PhD thesis. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 62, DOI  10.15480/882.13225
  • Kaminski P. and J. Grabe (2023): Triaxial testing methodology for gassy soils. In: Geotechnical Testing Journal 46(6), DOI 10.1520/GTJ20230296
  • Kaminski P. and J. Grabe (2023): Triaxial set-up and procedure to investigate the shear strength of gassy sediment. In: Proceedings of 9th International SUT Offshore Site Investigation and Geotechnics Conference (OSIG) 2023 in London/UK – Innovative Geotechnologies for Energy Transition, pp. 447-452, published by the Society for Underwater Technology, ISBN 978-0-906940-59-4
  • Kaminski P., Grabe J. (2023): Triaxial testing methodology for gassy soils. In: Proceedings of 8th International Symposium on Deformation Characteristics of Geomaterials 2023 in Porto (IS-PORTO), in: Geotechnical Testing Journal 46(6), URL: https://www.astm.org/gtj20230296.html
  • Kaminski P., Grabe J., Zeest F. (2023): Miniaturized testing device for the qualitative analysis of gas exsolution in soil. In: Proceedings of 42nd International Conference on Ocean, Offshore and Arctic Engineering (OMAE) 2023 in Melbourne, Australia, paper No. OMAE2023-101605
  • Kaminski P., Grabe J. (2023): Earthquake loading on submarine slopes preconditioned by marine gas: estimating the triggering potential based on stability analyses. In: Proceedings of 3rd JTC1 Workshop on Impact of Global Changes on Landslide Hazard and Risk 2023 in Oslo/Norway, V. Capobianco et al. (eds.), pp. 71–74, URL https://jtc1-2023.com
  • Kaminski P. and J. Grabe (2023): Triaxial set-up and procedure to investigate the shear strength of gassy sediment. In: Proceedings of 9th International SUT Offshore Site Investigation and Geotechnics Conference (OSIG) 2023 in London/UK – Innovative Geotechnologies for Engery Transition, pp. 447–452, published by the Society for Underwater Technology, ISBN 978-0-906940-59-4
  • Kaminski P., Grabe J. (2023): Triaxial testing methodology for gassy soils. In: Proceedings of 8th International Symposium on Deformation Characteristics of Geomaterials 2023 in Porto (IS-PORTO), Geotechnical Testing Journal 46(6), URL: https://www.astm.org/gtj20230296.html
  • Kaminski P., Grabe J., Zeest F. (2023): Miniaturized testing device for the qualitative analysis of gas exsolution in soil. In: Proceedings of 42nd International Conference on Ocean, Offshore and Arctic Engineering (OMAE) 2023 in Melbourne, Australia, paper No. OMAE2023-101605
  • Kaminski P., Grabe J. (2023): Earthquake loading on submarine slopes preconditioned by marine gas: estimating the triggering potential based on stability analyses. In: Proceedings of 3rd JTC1 Workshop on Impact of Global Changes on Landslide Hazard and Risk 2023 in Oslo/Norway, V. Capobianco et al. (eds.), pp. 71-74, URL https://jtc1-2023.com
  • Sager T.F., Urlaub M., Kaminski P., Papenberg C., Lastras G., Canals M., and C. Berndt (2022): Development and emplacement of Ana Slide, Eivissa Channel, Western Mediterranean Sea. In: Geochemistry, Geophysics, Geosystems 23, DOI: 10.1029/2022GC01046
  • Kaminski P., Grabe J., Sager T.F. and M. Urlaub (2022): Decline in slope stability as a consequence of gassy soil in submarine slopes on the Balearic Promotory. In: Proceedings of 41th International Conference on Ocean and Artic Engineering (OMAE) 2022 in Hamburg/Germany, paper No. OMAE2022-81151
  • Kaminski P., Sager T., Grabe J. und M. Urlaub (2021): A new methodology to assess the potential of conjectural trigger mechanisms of submarine landslides exempified by marine gas occurrence on the Balearic Promonory. In: Engineering Geology 295. No. 106446, DOI: 10.1016/j.enggeo.2021.106446
  • Kaminiski P. and J. Grabe (2020): On the possibility of gassy soils triggering submarine slope instabilities. In: Proceedings of 2nd International Conference on Energy Geotechnics (ICEGT 2020), E3S Web of Conferences 205, 12006, DOI: 10.1051/e3sconf/202020512006
  • Kaminski P., Urlaub M., Grabe J. and C. Berndt (2019): Geomechanical behaviour of gassy soils and implications for submarine slope stability – a literature analysis. Special Publication No. 500, Geological Society, DOI: 10.1144/SP500-2019-149

Project relevant student works

  • Nehls K. (2019): Entwicklung eines Versuchsstandes für Modellversuche zur Versagensinitiierung von Unterwasserböschungen durch Gasmigration. Project work

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Holistic approach for the design of single piles and pile groups

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/37-1 und 37-2 sowie WI 3810/5-1 und WI 3810/5-2
  • Project partner: Prof. Dr.-Ing. habil. Thorsten Wichtmann, Ruhr Universität Bochum, Lehrstuhl für Bodenmechanik, Grundbau und Umweltgeotechnik
  • Duration: 01.09.2019 to 31.08.2025 (72 months)
  • Staff: Anne Hagemann
  • Status: Ongoing project, DFG proposal, DFG interim report and continuation proposal

Keywords

Pile, pile group, physical modelling, Subgrade Reaction Method (SRM), Multiaxial simple shear testing with cyclic loading

Project description

The long-term load-deformation behaviour of piles under cyclic axial and horizontal loads is of great importance for the design of pile foundations. Predicting this behaviour is associated with large uncertainties due to the different types of cyclic loading and an extremely large number of load cycles compared to conventional engineering structures. A design approach is required that reflects the soil behaviour under cyclic and high-cyclic loading and the specific load behaviour of the structure. Existing approaches already show significant uncertainties when applied to monotonic pile loading.

The main objective of this research project is to further develop a design approach based on an existing bedding model called SRMHYP, which is currently designed for cyclic lateral loading of single piles in sand. This model is intended to cover the following cases at the end of the project: 

  • single piles and pile groups,
  • sand and clay, 
  • cyclic and highly cyclic axial and lateral loading, 
  • soil stiffness at small and large strains, 
  • rate-independent behaviour of sand and rate-dependent behaviour of clay, 
  • effects due to pile installation and growth effects.

The results from centrifuge tests, numerical simulations and existing results from field tests are used to validate the SRMHYP model. All planned experiments, models and numerical simulations are designed for two defined model soils, namely a fine uniform quartz sand as a representative of cohesionless soils and a kaolin as a representative of cohesive soils.

The results of the soil mechanics laboratory tests on sand and kaolin with cyclic loading serve as input variables for the SRMHYP model, for the further development of a stress-strain model for kaolin, for the further development of accumulation models for sand and kaolin, and for the calibration of hypoplastic and visco-hypoplastic models for sand and kaolin. The results of the centrifuge tests on piles in sand and kaolin under cyclic loading and under defined conditions serve to validate the SRMHYP model and also the numerical simulations, as they are carried out under a realistic stress level. The numerical simulation of piles under cyclic and highly cyclic loading is based on a continuum approach and the Finite Element Method (FEM). The further developed material and accumulation models described above are applied here.

Furthermore, changes to the contact model for the pile/soil contact area and work on material routines for the FE program are required. The results of the numerical simulations serve to abstract the simpler and less computationally intensive SRMHYP model. Simulation models are validated using the results from centrifuge and field tests.

The first funding period focuses on individual piles. In the second funding period, the focus is on simplifying the calibration procedures for the two accumulation models and incorporating pile installation, set up effects and pile groups.

Project relevant publications

  • Hagemann A. (2024): Numerische Modellierung der dynamischen Boden-Struktur-Interaktion am Beispiel eines Offshore-Monipiles. In: Tagungsband zum Kolloquium Numerik in der Geotechnik 2024 in Karlsruhe, Bundesanstalt für Wasserbau (Publikation des Tagungsbands steht aus)
  • Hagemann A. (2024): On cyclic and dynamic pile-bearing behaviour. Dissertation. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 61, DOI: 10.15480/882.13265
  • Hagemann A. and J. Grabe (2024): On the validity of Miner's rule for pile foundations in sand. In: Proceedings of 43rd International Conference on Ocean, Offshore and Arctic Engineering (OMAE) 2024 in EXPO/Singapore, paper No. OMAE2024-124051
  • Stark A. und J. Grabe (2023): Zur numerischen Modellierung des zyklischen und dynamischen Tragverhaltens von Offshore-Monopfählen. In: Tagungsband zum Pfahl-Symposium 2023 in Braunschweig, Mitteilung des Instituts für Geomechanik und Geotechnik der Technischen Universität Braunschweig, Heft 113, Band 1, S. 149–160
  • Stark A., Grabe J. (2022): Ein Bettungsmodell zur Prognose des Langzeitverhaltens von Monopiles in Sand. In: Tagungsband zum Workshop Numerische Methoden in der Geotechnik 2022 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg, Heft 53, S. 57–75
  • Stark A., Breidenstein S. and J. Grabe (2022): On the validity of Miner's rule and its application in offshore pile design practice. In: Proceedings of 41th International Conference on Ocean, Offshore and Arctic Engineering (OMAE) 2022 in Hamburg/Germany, paper No. OMAE2022-81150
  • Stark A. und J. Grabe (2021): Zur bodendynamischen Strukturdämpfung von Offshore-Windenergieanlagen. In: Bautechnik 98(12):921–929, DOI: 10.1002/bate.20200010
  • Hagemann A. und J. Grabe (2019): Schwingungsverhalten einer Offshore-Windenergieanlage unter dynamischer Anregung. In: Tagungsband zur Fachsektionstagung Geotechnik 2019 in Würzburg, Deutsche Gesellschaft für Geotechnik e. V. (Hrsg.), S. 352–357

Project relevant presentations

  • Stark, A. (2019): Numerisches Modell zur Berechnung des Verformungsverhaltens von Monopfählen unter hochzyklischer Horizontalbelastung. At: HTG-Kongress 2019, Lübeck, Germany
  • Hagemann A. (2019): Numerical model to predict the displacement of piles under cyclic lateral loading using a new hypoplastic spring element. At: DENSER Workshop, Norwegian Geotechnical Institute, Oslo, Norway

Project relevant student works

  • Backes H. (2020): Experimentelle Untersuchungen zum Verhalten von Sand unter zyklischer Last im multidirektionalen Einfachschergerät. Bachelor thesis
  • Kaperschmidt C. (2020): Untersuchungen zum Einfluss der Porenzahl auf verschiedene Modellierungsansätze für das zyklische Last-Verformungsverhalten nicht bindiger Böden. Bachelor thesis
  • Eberhard O. (2019): Numerische Modellierung des Verhaltens von Sand unter zyklischer Last aus veränderlicher Richtung. Bachelor thesis
  • Kaiser H. (2019): Kalibrierung eines hypoplastischen Boden-Struktur-Modells an Hamburger Sand. Bachelor thesis
  • Cortez A. (2019): Experimentelle Untersuchungen zum Verhalten von Sand unter zyklischer Last aus veränderlicher Richtung. Bachelor thesis
  • Molla D. (2018): Numerisches Modell zur Berechnung des Verformungsverhaltens von Monopfählen unter zyklischer axialer Belastung. Bachelor thesis

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Investigation of the causes or influencing factors of the low load-bearing capacity of the steel piles in the lower outer harbour of the Niederfinow ship lift

Status: 26.11.2024
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General data

  • Customer: Bundesanstalt für Wasserbau (BAW), TUTECH project 176079
  • Duration: 01.12.2019 bis 30.11.2022
  • Sachbearbeiter: Christopher Tinat (01.12.2019 to 31.01.2021), Diaa Alkateeb (01.02.2021 to 30.11.2022)
  • Status: Completed project, internal report

Project description

Problem  During the construction of the new Niederfinow boat lift, the bank walls of the lower project (see Figure below) were to be anchored back with steel driven piles. For the preliminary design, the characteristic limit values ​​of the skin friction were specified in the geotechnical report based on empirical values ​​taking into account the existing soil types. These are in the range of usual empirical values ​​for driven piles. To verify the tensile load capacity derived from the assumptions of the preliminary design, two static test loads were performed on vertical steel driven piles at three locations. The resistances to the pulling out of the piles measured in this way were significantly lower than the forecast values ​​and corresponded to only 17 to 49 % of the planned test loads.

As part of an initial root cause analysis, additional subsoil surveys were carried out at the test loading locations, which confirmed the layer structure of the geotechnical report. Based on the driving protocols and a visual inspection of the removed steel driven piles, no abnormalities could be identified that would indicate a reduced load-bearing capacity under tensile load.

 

Figure: Lower outer harbour at Niederfinow Ship Lift under construction on 04.03.2020 (photo credits: Christopher Tinat, TUHH)

 

Objective  Driven steel piles are a common and proven anchoring element in waterway administration construction projects and in port construction in general. The primary objective of the research project was therefore to identify the causes and influencing factors on the low load-bearing capacity of driven steel piles subjected to tension.

Methods  The research project involved numerical simulations and experimental investigations. The experimental investigations will examine the friction behaviour at the steel-soil interface and model tests will be carried out. The analysis of the tensile behaviour of steel beam profiles will be carried out using numerical simulations based on the Finite Element Method (FEM), taking into account the impact driving during the installation process. The zipper technique and the Coupled Eulerian-Langrangian (CEL) approach was used for this.

Project relevant publications

  • Alkateeb D., Künzel A., Dogan A. und J. Grabe (2023): Messtechnische Begleitung von Pfahlprobebelastungen an Rammpfählen in Niederfinow. In: Tagungsband zum Pfahl-Symposium 2023 in Braunschweig, Mitteilung des Instituts für Geomechanik und Geotechnik der Technischen Universität Braunschweig, Heft 113, Band 1, S. 351–368
  • Alkateeb D. and J. Grabe (2022): On the application of analytical methods and empirical values for the determination of the pull-out resistance of driven steel piles. In: Proceedings of 10th International Conference on Physical Modelling in Geotechnics (ICPMG) 2022 in Daejon/Korea, Korea Geotechnical Society, M. Chung et al. (eds.), pp. 844–848, ISBN: 978-89-952197-7-5
  • Alkateeb D. (2022): Finite-Element basierte Prognose der Tragfähigkeit von Stahlrammpfählen am Beispiel des Bauvorhabens Schiffshebewerk Niederfinow. In: Tagungsband zum Workshop Numerische Methoden in der Geotechnik 2022 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg, Heft 53, S. 221–236

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Microscale observation of hydraulic-mechanical behaviour of unsaturated granular soils using Computed Tomography (CT)

Status: 25.10.2023
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project  MI 2397/2-1 bzw. DFG 401096010
  • Duration: 16.01.2020 to 15.01.2022 (24 months)
  • Staff: Dennis Heinrich
  • Status: Project completed, DFG interim report and continuation proposal

Keywords

Capillarity, capillary effects, Computed Tomography (CT), in-situ CT scan, Lattice Boltzmann Method (LBM)

Project description

Problem  The focus of the project is on capillary effects in unsaturated soils, where the pore space of the soil is completely filled with the fluids water and air with varying volume fractions. This includes the investigation of the interaction between capillary water present in the pore space and any air inclusions present with the grain structure and the effects on the mechanical, hydraulic or hydromechanical properties of porous granular soils.

The influence of capillary water is usually determined in soil mechanics in macroscopic laboratory tests and is important from the perspective of construction practice, as pore water often provides load-bearing reserves for structures. However, the variability of capillary effects, in particular the reduction of the so-called apparent cohesion or capillary cohesion when the soil is saturated and dried out. This is sometimes responsible for serious natural disasters such as landslides in many regions of the world. An investigation of the micromechanical or microhydraulic processes can lead to a better understanding of these macroscopic effects.

The relationship between the degree of saturation of a soil and macroscopically measured capillary pressures is also non-linear. On the one hand, irrigation, and drainage processes must be differentiated, but on the other hand, dynamic effects in the pore water flowing through the pore space must also be taken into account. The hydraulic properties should then be related to the mechanical properties, for example the shear strength.

Overall, there is currently little knowledge about the microscopic processes involved in the flow through partially saturated soils and the associated changes in mechanical properties. This is where the research project comes in to continue and expand experiments already carried out in the past and to increase the existing database.

Objectives  The following key questions should be clarified:

  • What differences arise in the distribution of pore air and pore water or the degree of saturation as well as the shape, curvature, and surface of the capillary menisci in granular soils under monotonic and cyclic, i.e. hysteretic, hydraulic drainage and irrigation paths?
  • How do the degree of saturation distribution and the capillary bridges change under mechanical stress and deformation of the grain skeleton by compression and shear, as well as during temporal decomposition of the sample by evaporation?
  • What are the relationships between microscopic and macroscopic mechanical behaviour of partially saturated granular soil under compression / shear with regard to shear strength and volume change of the grain skeleton (contractancy/dilatancy)?
  • By comparing ideal glass spheres with natural sand grains, can important microscopic parameters such as grain shape or grain surface area be identified that influence the hydraulic-mechanical behaviour at unsaturated states?

Methods  In order to quantify the capillary effects at the micro level, the first phase of the project will use Computer Tomography /CT) technology, which allows three-dimensional cross-sectional images of material samples to be created and then visualized and analysed on the computer. The resolution here is in the order of a few micrometers and enables the separation of the individual material phases and even the extraction of individual grains of sand. It is also possible to measure the curvature of capillary bridges of the pore water between individual soil particles.

The test equipment used must be miniaturized for this purpose. This is done with specially developed mechanical components that are controlled using the Raspberry Pi single-board computer and—where possible—automated. A miniaturized uniaxial compression device and an apparatus for cyclical watering and dewatering of the material samples to be examined are available.

In addition, the macro- and microscopically determined test results and material parameters are to be reproduced using numerical simulations. In particular, approaches are needed for an efficient and physically correct description of the contact between individual soil particles as well as the contact between the solid phase and the fluids. A promising approach for this is the Lattice-Boltzmann Method (LBM).

The test material used consists primarily of monodisperse sphere packings. In particular, spheres made of soda-lime glass are used. These are easier to transfer to simulation models in the first step than particles of any shape. However, the aim is also to use the model sand “Hamburg Sand” and a polydisperse mixture of glass spheres with an almost identical grain distribution curve based on this in order to depict the general case.

 

Project relevant publications

  • Milatz M., Heinrich D. und J. Grabe (2023): Experimentelle und numerische Bodenmechanik auf der Partikel- und Porenskala. In: Tagungsband zu Fachsektionstage Geotechnik (4. Bodenmechanik-Tagung) 2023 in Würzburg/Germany, S. 382–387, URL https://www.dggt.de/index.php?option=com_content&view=article&id=397&Itemid=60, ISBN 978-3-946039-10-5
  • Heinrich D. and M. Milatz (2023): Capillary cohesion of different granular materials determined from uniaxial compression and water retention tests. In: Proceedings of 8th International Conference on Unsaturated Soils 2023 in Milos/Greece, E3S Web of Conferences 382, No. 02003, DOI 10.1051/e3sconf/202338202003
  • Milatz M. and D. Heinrich (2023): Pore scale investigation of unsaturated granular soil behaviour by means of in situ CT experiments. In: Proceedings of 8th International Conference on Unsaturated Soils 2023 in Milos/Greece, E3S Web of Conferences 382, No. 11004, DOI 10.1051/e3sconf/202338211004
  • Heinrich D. and M. Milatz (2022): UNSAT-Pi - A miniaturized test apparatus for examining the uniaxial compressive strength of partially saturated granular media during CT imaging. In: TUHH Open Research (TORE), DOI 10.15480/336.4393, data repository including CAD design data, circuit diagrams, and control software
  • Heinrich D., Milatz M., Schröder M. (2022): Zur Untersuchung bodenmechanischer Zusammenhänge mittels Computertomografie. In: Tagungsband zur 37. Baugrundtagung 2022 in Wiesbaden/Germany, S. 201–210, Deutsche Gesellschaft für Geotechnik e. V. (DGGT)
  • Heinrich D. and M. Milatz (2022): On the application of single-board computers and physical computing for the investigation of the water retention curve of unsaturated granular soils. In: Proceedings of 10th International Conference on Physical Modelling in Geotechnics (ICPMG) 2022 in Daejon/Korea, Korea Geotechnical Society, M. Chung et al. (eds.), pp. 334–337, ISBN: 978-89-952197-7-5
  • Heinrich D. und M. Milatz (2022): UNSAT Pi-2 - A miniaturized flow cell apparatus for measuring the water retention curve of granular media during CT imaging. In: data repository including CAD design data, circuit diagrams and control software, TUHH Open Research (TORE), DOI 10.15480/336.4394

Project relevant student works

  • Jäntsch, M. (2021): Untersuchung des Kollapsverhaltens teilgesättigter granularer Medien durch Evaporation des Porenwassers mithilfe der Mikro-Computertomografie (Investigations of collapse-behaviour of unsaturated granular media due to evaporation of pore water by means of micro computed tomography). Bachel thesis

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Influence of uncertain soil models on the desgn of geotechnical constructions

Status: 26.11.2024
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General data

  • Funding: Hamburg University of Technology (TUHH)
  • Duration: 01.01.2020 to 31.12.2023
  • Staff: Timon Burgwedel
  • Status: Project cancelled

Project description

As part of the research project, the influence of uncertain soil models on the numerically based design of geotechnical structures is being investigated. As part of the DFG project GR 1024/27-1, the focus was on the fuzzy nature of CPT data from a test field and of CPT data and material parameters for another test field. The fractal nature of the uncertainty was highlighted. The focus of the present project lies on the generation of fractal random fields for the initial values ​​of the soil state variables, as well as FE analyses based on these fractal random fields. On the basis of the existing results of Cone Penetration Tests (CPT) and laboratory tests for two test fields, the relevant fuzzy variables are first identified. This was shown as an example for the choice of a specific stress-strain model. Furthermore, the data from the “Kaiser-Wilhelm-Höft” test field, which was obtained in 2019, will be statistically processed. In the second step, random fields are generated, for example, a random walk process is generated for the number of pores, the spatial distribution of which is limited by the experimentally observed CPTs. For this purpose, a random walk process is provided for in the application. Finally, a series of boundary value problems are solved numerically using the deterministic Finite Element Method (FEM) and the stochastic Random Finite Element Method (RFEM) on the basis of the previously determined fractal random fields. This includes 1D, 2D and 3D analyses for the two test fields. In the course of RFEM, strategies are pursued to minimize the computational effort, which are being developed, for example, as part of the DFG priority program SPP 1886. The differences between numerically based designs with classic FEM and with RFEM are compared and conclusions are drawn about the required investigation effort in the course of the subsoil investigation.

 

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Penetration and Extraction of structured in saturated soils

Status: 26.11.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH)
  • Duration: 01.05.2020 bis 30.04.2023
  • Staff: Diaa Alkateeb
  • Status: Project completed

Project description

The focus of the research project is on mechanical-hydromechanical-coupled processes at the base of piles that are driven into the saturated soil or pulled out of the saturated soil:

  • When driving piles, large movements of the pile, large relative movements between the pile and the ground and large soil deformations occur. In saturated soil, pore water excess pressure usually occurs. During the driving process, contact at the base of the pile can remain or be lost for a short time (keywords “slow/fast driving” and “cavitary driving”). If contact is lost between the component and the ground, an area is created that is filled with pore water or water vapour, but not with a grain structure (keyword “cavitation”).
  • When extracting piles from saturated soil, in addition to the shear resistance between the pile and the soil, two further resistances potentially occur at the pile base: (1) A downward force due to the suction effect, which depends on the pulling speed of the pile and the permeability of the soil at the pile base. The maximum value of the corresponding force is the product of the cross-sectional area and the maximum negative pressure in the pore water. (2) If the soil in the area of ​​the pile base is cohesive, an normal adhesion force can also act. When the pile is pulled out, a zone can also form under the pile base in which the grain skeleton and the pore water separate. In the limiting case, cavitation occurs. This is the formation and dissolution of vapour-filled cavities (vapour bubbles) in liquids. Two limiting cases are distinguished, between which there are many transitional forms: (1) In vapour cavitation or hard (transient) cavitation, the cavities mainly contain vapour from the surrounding liquid. Such cavities collapse under the influence of external pressure by bubble implosion. (2) In soft gas cavitation, gases dissolved in the liquid enter the cavities and dampen their collapse; in stable gas cavitation, they prevent it.

The focus of the research project was the numerical simulation of the processes described above. The requirements for corresponding simulation models include the modelling of large component movements, large relative movements between pile and soil, large soil deformation, possibly a separation of grain skeleton and pore water and possibly cavitation in extreme cases.

Hint: the contact loss between piles and subsoil due to vibratory pile driving in saturated soils is investigated in the ongoing research project KORA.

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Numerical simulation of the penetration of ship anchors into the seabed

Status: 26.11.2024
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General data

  • Customer: 50hertz Transmission GmbH
  • Duration: 01.06.2020 to 31.08.2022 (24 months)
  • Staff: Duy Anh Dao
  • Status: Project completed, internal report

Project description

A key challenge in implementing the energy transition in Europe is ensuring a high level of grid stability. Due to the natural irregularities in the weather, offshore wind farms temporarily produce a surplus of energy, which leads to an overload of the power grid. While effective storage is not yet possible in Germany, Sweden has effective pumped storage power plants. As a result, the submarine cable connection, Hansa PowerBridge, is to be laid between Germany and Sweden. This is intended to balance out the fluctuating power generation from renewable energies.

Damage to offshore submarine cables is often caused by ships' anchors getting caught. To protect the cables from this, they are laid in the seabed. Safety aspects are of the utmost importance when determining the laying depth. But economic factors must also be taken into account when dimensioning.

As part of the research project, the penetration and braking behaviour of various ship anchors in both cohesive and non-cohesive seabeds will be investigated using numerical simulations under different conditions. The aim is to provide answers to the following questions:

  • How deep ship anchors penetrate into the seabed?
  • How much the sea cable is damaged due to the penetration?

The analyses was carried out by numerical simulations based on the Finite Element Method (FEM) with direct explicit time integration. Due to the expected large bottom deformations, the Coupled Eulerian-Langrangian (CEL) approach was used. Due to the high towing speeds, undrained conditions were assumed in the seabed. The numerical simulations were used to observe the anchor behaviour and analyze the penetration mechanism. In addition, a variation of the input parameters was intended to provide information about the influence of the individual factors on the penetration depth.

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Numerical modelling of partially cemented soils in the stagnation domain

Status: 26.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/41-1 and 41-2 as well as DU 405/17-1 and 17-2
  • Project partner: Prof. Dr.-Ing. habil. Alexander Düster (Institut für Konstruktion und Festigkeit von Schiffen, TUHH)
  • Duration: 2020 to 2023 (36 + 20 months)
  • Staff: Michalis Komodromos (36 months), Elnaz Hadjiloo (20 months)

Project description

The primary objective of the planned research project is to gain a better understanding of the micromechanical deformation behaviour of multiphase porous composite materials. To this end, a multiphase composite material that is common in civil engineering and used in many problems in geotechnics in particular will be examined in more detail: cement-bound sand. For example, self-hardening suspension can be used as a supporting fluid in the manufacture of diaphragm walls. Due to the manufacturing process, there are transition zones at the edges of the component between a grain structure that is almost completely filled with cement and a pure grain structure. In this area, known as the stagnation area, the load transfer depends on the position and contact points of the individual grains. Loads are carried on the one hand by the coherent cement matrix and on the other hand by the sand grains embedded in it. The load transfer is strongly influenced by the heterogeneous arrangement and sphericity of the individual grains, the degree of mixing and the cement content. In order to improve macroscopic FE models that are relevant for practical use, a bridge is to be built between the microscopic and macroscopic material behaviour of porous composite materials. Based on imaging techniques such as X-ray Computed Tomography (CT), three-dimensional FE models are to be created directly from the image data obtained by scanning cement-bound sand samples. Numerical methods can be used to carry out deformation analyses on the models obtained in this way. The Institute for Geotechnics and Construction Management (Prof. Grabe) focusses on the Finite Element Method (FEM), and the Institute for Ship Design and Strength (Prof. Düster) is further developing the Finite Cell Method (FCM). These two numerical approaches are to be applied to the microstructural problems and optimized in the course of the planned research project. The aim is to derive macroscopic material properties of the complex multiphase microstructures through numerical homogenization. This makes it possible to characterize the macroscopic material behaviour of such composite materials. The macroscopic material behaviour will be investigated using laboratory tests. Uniaxial compression tests and triaxial tests on sand samples with different cement contents are planned. Due to the extensive planned investigations in the soil mechanics laboratory, on the CT scanner and the numerical investigations and developments, elastic material behaviour will initially be assumed in this first project phase. In a possible second project phase, nonlinear material models will be used, among other things, to investigate larger deformations or to model damage in the composite material.

Project relevant publications

  • Komodromos M., Gorji M., Düster A., Grabe J. (2024): Implementation of linear strain elements for image-based Finite Element Analysis of cemented natural sand. In: Computers and Geotechnics 174, No. 106606, DOI 10.1016/j.compgeo.2024.106606
  • Gorji M., Komodromos M., Garhuam W., Grabe J., Düster A. (2024): Geometry smoothing and local enrichment of the finite cell method with application to cemented sand. In: Computational Mechanics, DOI: 10.1007/s00466-024-02512-1
  • Komodromos M., Gorji M., Düster A., Grabe J. (2023): Investigation of the load sustaining micro mechanisms of cemented sand using mesocale FEM approach. In: Computers and Geotechnics 162, 105656, DOI: 10.1016/j.compgeo.2023.105656
  • Komodromos, M., Gorji, M., Düster, A., & Grabe, J. (2023). On the load bearing mechanisms of cemented granular material: A mesoscale FE approach. In: Proceedings in Applied Mathematics and Mechanics, e202300037, DOI
    10.1002/pamm.202300037
  • Komodromos M., Stamati O., Grabe J. (2023): Mesoscale FEM approach on cemented sands: generating and testing the digital twin. In: Proceedings of 8th International Symposium on Deformation Characteristics of Geomaterials 2023 in Porto (IS-PORTO), ISSMGE Online Library, URL https://www.issmge.org/uploads/publications/121/122/isdcg2023-36-1-c.pdf
  • Hüsener N., Helfen L., Komodromos M., Milatz M., Tengattini A. and C.M. Toffoli (2023): Combined X-ray- and neutron-tomography investigation of capillary collapse in unsaturated granular soils subjected to loading. CT data repository, Institut Laue-Langevin (ILL) in Grenoble/France, DOI 10.5291/ILL-DATA.1-07-11
  • Komodromos M., Stamati O., Düster A., Gorji M. and J. Grabe (2023): Mesoscale FEM approach on cemented sand: challenges and implementation of high order elements. In: Proceedings of 10th European Conference on Numerical Methods in Geotechnical Engineering 2023 in London/UK, DOI 10.53243/NUMGE2023-96
  • Gorji M., Komodromos M., Grabe J., Düster A. (2023): Imaged-based analysis of complex microstructures using the finite cell method. In: Proceedings in Applied Mathematics and Mechanics 23(1):e202200291, DOI 10.1002/pamm.202200291

Project relevant student works

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On the three-dimensional load-bearing bahaviour of combined steel sheet pile walls

Status: 26.11.2024
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General data

  • Funding: Forschungsvereinigung Stahlanwendung e. V. (FOSTA-Verbundprojekt 1480)
  • Project administration: Arbeitsgemeinschaft industrieller Forschungsvereinigung (AiF)
  • Project partner: Prof. Dr.-Ing. Ulrike Kuhlmann, Institut für Konstruktion und Entwurf, Universität Stuttgart
  • Duration: 01.01.2021 bis 30.06.2023 (30 months)
  • Staff: Jannik Beuße
  • Status: Project completed, final report, PhD thesis published in institute's series (Vol. 59)

Project description

Kombinierte Spundwände werden hauptsächlich im Kaimauerbau als maßgebendes Tragelement eingesetzt. Unter Anwendung der gültigen Nachweisformate zeigt sich, dass rechnerisch eine Vielzahl der bestehenden Kaimauern nicht mehr standsicher ist, obwohl diese Konstruktionen der bewährten Praxis entsprechen. Die Bemessung erfolgt hierbei zumeist zweidimensional unter dem Ansatz einer Gewölbewirkung zwischen den Tragbohlen, sodass diese den Erddruck und die Zwischenbohlen lediglich den Wasserdruck aufnehmen. Zur Beschreibung des räumlichen Tragverhaltens von kombinierten Spundwänden liegen nur unzureichende Informationen vor (vgl. Bild).

 

Bild: Vertikale (links) und horizontale (rechts) Gewölbewirkung einer kombinierten Stahlspundwand

Die Zielsetzung des Forschungsvorhabens ist die Erfassung der tatsächlichen Belastung der Zwischen- und Tragbohlen infolge Erd- und Wasserdruck sowie deren Beanspruchung unter Berücksichtigung ihrer räumlichen Systemtragwirkung. Durch die Klärung des Lastabtrags werden Überdimensionierungen dieser Bauteile vermieden. Durch die Einbeziehung der räumlichen Tragwirkung von kombinierten Stahlspundwänden inklusive der Verankerung kann deren Auslegung optimiert werden. Hierzu sollen folgende Fragen geklärt werden:

  1. Horizontales / räumliches Tragverhalten

    Fragekomplex 1: Frage 2: Frage 3:

    • Wann kommt es zu einer Ausbildung eines horizontalen Druckgewölbes und wie teilen sich die Belastungen auf die Tragbohlen und die Zwischenbohlen auf?
    • Welchen Einfluss hat das zusätzlich auftretende vertikale Gewölbe infolge des Erd- und Wasserdrucks?
    • Wird der räumliche Erdwiderstand hinreichend genau abgebildet?
    • Welchen Einfluss hat die Kombination aus räumlicher Einwirkung und räumlichem Widerstand?
    • Wie groß sind dabei die Widerstände der Stahlelemente bei einer veränderlichen Belastung und bei einer Berücksichtigung einer Teileinspannung durch realitätsnahe Lagerungsbedingungen
    • Wie beeinflusst die Rammung der Pfähle hinter der kombinierten Wand das Tragverhalten und wie kann dieser Einfluss berücksichtigt werden?
    • Wie können die Zusammenhänge aus den Fragen 1 und 2 in einem idealisierten Bemessungsmodell vereinfacht abgebildet werden?

  2. Vertikales Tragverhalten

    Fragekomplex 4:

    • Wie kann die Konsistenz und Wirtschaftlichkeit des vereinfachten Knicknachweises bei gleichzeitiger Momentenbeanspruchung nach Eurocode EN 1993-5 und DIN EN 1993-1 sichergestellt werden?
    • Wie sollen die Widerstände im Boden für den vertikalen Nachweis ermittelt werden

Das Arbeitsprogramm des Forschungsvorhabens umfasst experimentelle, numerische und analytische Untersuchungen. Unter anderem sind Modellversuche im Labor geplant. Die dabei ermittelten Belastungen und Lagerungsbedingungen sollen auf Versuche im Originalmaßstab in der Versuchseinrichtung an der Universität Stuttgart übertragen werden, sodass die Bauteile realitätsnah geprüft werden können. Für die Tragbohle sollen für die Modifizierung des vereinfachten Knicknachweises infolge Normalkraft und Biegung Knickversuche an Stützen durchgeführt werden. 

Durch die Anwendung bislang ungenutzter Potenziale versprechen wir uns eine wirtschaftliche und planungstechnische Optimierung und gleichzeitig eine Vereinfachung der Auslegung von kombinierten Spundwänden. Das führt insgesamt zu einer Verbesserung der Wettbewerbsfähigkeit und somit des Marktanteils der Stahlbaulösungen im Marktsegment der großen Kaimauern von Hafenanlagen.

Project relevant publications

  • Beuße J. (2023): Zur Einbringung und zum Tragverhalten von kombinierten Spundwänden von Ufereinfassungen. Dissertation. Technische Universität Hamburg (TUHH), Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 59

Project relevant student works

  • Hillebrand (2021): Untersuchung zum Einfluss der Kaiplattenpfähle auf den wirkenden Erddruck auf Kaimauern
  • Martens (2021): Zum räumlichen Tragverhalten kombinierter Spundwände infolge der Installation von Kaiplattenpfählen

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Adhesion between tools and cohesive soils

Status: 25.11.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH)
  • Duration: 01.03.2021 to 28.02.2023 (24 months)
  • Staff: Maximilian Schröder
  • Status: Completed project

Project description

Adhesions occur during various (specialised) geotechnical engineering works. Tunnelling in cohesive ground, in particular, is associated with a number of technical difficulties, as adhesions occur on the cutting wheel, its passages and tools, the excavation chamber and the transport system. This leads to delays in the schedule and economic losses, as the tunnelling performance is reduced. It is also possible for the machine to come to a standstill. Extensive cleaning work then becomes necessary. Increased wear is also associated with clogging. Up to now, the extracted soil has been conditioned in practice using additives to reduce sticking. The conditioned soil must then be disposed of at great expense.

There are a number of classification attempts to qualitatively characterize the soil's tendency to adhere and empirically developed classification diagrams that indicate the consistency of the soil at which adhesion is to be expected. However, the basic physical and soil mechanical adhesion mechanisms between soil and metal (cutting wheel) are still not fully understood. The aim of the research project is to shed light on the basic mechanisms of soil adhesion to tool surfaces in terms of soil physics and to describe the prevailing mechanisms. Based on this in-depth understanding, solutions for minimizing adhesion are to be developed.

Objectives

The following questions will be considered:

  • The adhesion between soil and a tool surface can be divided into a normal portion perpendicular to the surface and a tangential portion parallel to the surface. Both components must be determined in adhesion tests and brought into a soil-mechanical context.
  • Depening on the soil properties (especially its consistency) an adhesive failure along the interface or a shear failure inside the soil can occur. Dies führt insbesondere dazu, dass sich die reine Adhäsion versuchstechnisch oftmals nicht bestimmen lässt und verdeutlicht darüber hinaus, dass Adhäsionskräfte über die Trennfläche hinaus in den Bodenkörper hinein wirken. In den meisten Fällen beeinflusst die flüssige Phase des Bodens das Adhäsionsverhalten maßgeblich. Saugspannungen in ungesättigten Böden sollen nach Möglichkeit bestimmt und in einen potentialtheoretischen Zusammenhang gebracht werden. Darüber hinaus soll mithilfe der CT-Bildgebung sichtbar gemacht werden, was in der Trennfläche zwischen Boden und Werkzeugoberfläche geschieht.
  • Die Verklebungen am Schneidrad führen zu einem Anstieg des notwendigen Drehmoments und einer verringerten Vortriebsleistung. Versuchstechnisch sollen Abbohrversuche mit einem Miniaturschneidrad zeigen, welche Parameter die Vortriebsleistung bestimmen und ob sich gewonnene Erkenntnisse aus reinen Adhäsionsversuchen bestätigen lassen. Realistische Vortriebsszenarien, wie beispielsweise das Wiederanfahren nach Stillstand, sollen untersucht werden und optimale Vortriebsparameter zur Minimierung der Verklebung entwickelt werden. In miniaturistierten Modellversuchen soll mithilfe der CT-Bildgebung untersucht werden, wie sich der Boden durch ein Schneidrad bewegt und wie sich Verklebungen fortschreitend am Werkzeug einstellen.

Methods

  • Selection and characterization of suitable soils for testing
  • Adhesion testing (normal and tangential, including measurement of suction)
  • Miniaturized model tests (adhesion tests, drilling test) with CT-imaging
  • Drilling test with a tunnel cutting wheel model (see picture below)

       

Project relevant publications

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Project relevant supervised students

  • M. R.: Zur Bestimmung des Einflusses der Saugspannung auf die Adhäsion von Tonböden in Trennversuchen
  • N. R.: Zum Einfluss der Probenherstellung auf die Scherfestigkeit bindiger Böden
  • M. R.: Untersuchung der normalen Adhäsion eines Tonbodens mithilfe von Trennversuchen und Computer Tomographie (CT)

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Numerical modelling of water jet induced erosion in saturated sand

Status: 25.11.2024
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General information

  • Funding: Deutsche Forschungsgemeinschaft( DFG), project GR 1024/43-1
  • Duration: 01.06.2021 to 31.12.2023 (24 months), cost-neutral extension until 31.03.2024
  • Staff: Rahul Somasundaram

Project description

The objective of this research proposal is to better understand the physical processes during the erosion of soils with a fluid jet, especially the erosion of saturated sand with a water jet. This includes the propagation of the water jet, the soil erosion process, the transient propagation of the erosion front up to the maximal erosion range, the transport of suspended soil particles and finally the sedimentation of the particles. To achieve this objective, a novel concept called “geometrically combined resolved-unresolved CFD-DEM” method for the numerical investigation of the jet grouting process will be developed. The idea behind this new technique is that the erosion front of the jet, where a detailed resolution is required, will be modelled with resolved CFD-DEM. In the regions outside the erosion front, where the dynamics of fluid-particle interaction is much lower, unresolved CFD-DEM will be applied. This approach will ensure efficient modelling of a highly dynamic and large-scale process like water jetting at manageable computational costs and without compromising on the detail and accuracy where it is needed. Since the soil skeleton is dynamically moving, it becomes obvious that the transition of a soil particle from the unresolved to the resolved region (and vice versa) will need complex modelling algorithms. Further, keeping in mind that the “erosion front” is moving in time, the need for a dynamic adaption of the “resolved erosion front” becomes clear. The numerical model development will be accompanied by experimental investigations to validate the numerical model.

To reach the defined objectives a co-operation between Hamburg University of Technology/Germany and DCS Computing Linz/Austria is planned. DCS is developing the code CFDEM coupling, which is used in the research project. This cooperation is covered by the D-A-CH agreement (DFG in Germany and FWF in Austria).

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Investigation of geotechnical boundary value problems with soil-water interaction by means of Double-Point Material Point Method (2P-MPM)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), projects GR 1024/45-1 and GR 1024/45-2
  • Duration/staff:
    16.05.2021 to 15.02.2023 (45-1, Alexander Chmelnizkij, 21 months),
    01.03.2023 to 31.12.2023 (45-2, Alexander Chmelnizkij, 10 months),
    01.04.2024 to 30.11.2024 (45-2, Rahul Somasundaram, 8 months)
  • Status: Ongoing project

Project description

The aim of the research project is to develop a numerical method for simulating large deformations in geotechnical boundary value problems for two-dimensional (plane strain and axisymmetric) problems. For this purpose, the Material Point Method (MPM) is being further developed and adapted as a method. The Institute of Geotechnics and Construction Management is a member of the Anura3D MPM Research Community and has been jointly developing the MPM code Anura3D for the numerical solution of dynamically coupled initial boundary value problems in the field of geotechnics since 2014. The further development of the MPM for coupled problems, such as the simulation of saturated sand, is necessary in order to minimize the numerical errors of the method and thus increase the reliability of the simulation results. For this purpose, numerous modifications of the MPM have already been developed and investigated in mechanics, which can be generalized to coupled problems. The implementation of these developed methods is implemented in the MATLAB programme and checked for correctness using analytical solutions and available measurement data. The development and implementation of the modified MPM forms the focus of the first project phase, with subsequent validation. In a possible second project phase, further extensive validations will take place and the focus will be on increasing the efficiency of the implementation.

Project relevant publications

  • Chmelnizkij A. (2023): Improved Double-Point Material Point Method for dynamic geotechnical problems. In: Proceedings of 12th International Conference on Structural Dynamics 2023 in Delft/The Netherlands
  • Chmelnizkij A. (2023): Moving Last Squares Material Point Method for porous media. In: Proceedings of 10th European Conference on Numerical Methods in Geotechnical Engineering 2023 in London/UK, DOI 10.53243/NUMGE2023-75
  • Chmelnizkij A. (2023): Regularized MPM for porous media. PhD thesis. Technische Universität Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb, Heft 57, DOI 10.15480/882.4941
  • Chmelnizkij A. (2022): 2P-MPM für hochdynamische Einwirkungen - eine kompakte und effiziente Implementierung in MATLAB. In: Tagungsband zum Workshop Numerische Methoden in der Geotechnik 2022 in Hamburg, Veröffentlichungen des Instituts für Geotechnik und Baubetrieb der Technischen Universität Hamburg, Heft 53, S. 179–186

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Increasing the bearing capacity of geotechnical constructions using stabilization of shear zones (TGTSV)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/23-2
  • Duration: 01.06.2021 to 31.05.2023 (24 months)
  • Staff: Elnaz Hadjiloo
  • Status: Completed project, followed by project GR 1024/23-3

Project description

The primary objective of the research project was to increase the load-bearing capacity of geotechnical structures and reduce the earth pressure load on supporting structures by introducing consolidation materials into the shear joints in the ground. The sub-goals of the three funding periods are summarized below:

  • Computational determination of the position of the shear zones. Development of a procedure for computationally automated shear joint hardening, which is referred to below as Computational Shear zone Hardening (CSH). Experimental investigation of the suitability of hardening materials for the soil and technical implementation of shear zone hardening by means of physical modelling (1g model tests in the laboratory and centrifuge tests).
  • Further development of CSH through the use of advanced constitutive models for the soil and consideration of contact surfaces between the natural and the consolidated soil. This is referred to as CSH 2.0.
  • Extension of the range of applications of CSH 2.0 by combining it with multi-criteria numerical optimization and by taking into account loads that vary in time and space.

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Micro-mechanical modelling of unsaturated particle packings using CFD-DEM and computed tomography (MIME-UP)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG) - project GR 1024/46-1, and Österreichischer Wissenschaftsfonds (FWF) - project FWF I 5374
  • Project partner: DCS Computing GmbH, Linz/Austria
  • Duration: 01.05.2022 to 31.12.2024 (24 months)
  • Staff: Dennis Heinrich
  • Status: Ongoing project, interim report and continuation proposal

Project description

The focus of the research project is on investigating the influence of capillary effects in partially saturated sands on their mechanical and hydraulic behaviour. Experiments in an X-ray tomograph and numerical simulations are planned for this purpose. Resolved CFD-DEM coupling will be used for the numerical simulation of partially saturated sands. The existing method for the saturated soil will be extended by a two-phase formulation for the two pore fluids in order to take their influence into account. In order to be able to simulate triaxial tests, the interaction between the particle-fluid mixture and a deformable rubber membrane is also implemented in the CFD-DEM code. The microscale experiments carried out in the X-ray tomograph are used to validate the newly developed CFD-DEM. The experiments focus on the formation of capillary bridges during the dewatering of a sand column and on the deformation behaviour during a triaxial test. In order to achieve the goals set, a co-operation with DCS Computing GmbH from Linz/Austria has been established. DCS is developing the CFD-DEM coupling (CFDEM code), which will be used as part of the research project. The co-operation takes place within the framework of the D-A-CH agreement between Germany (DFG; weave lead agency) and Austria (FWF).

Project relevant publications

  • Heinrich D., Niemann M., Goniva C., Kloss C., Grabe J. (2024): Membrane Particle Interaction in Triaxial Testing: FEM-DEM Coupling and CT Imaging Insights. In: Book of Abstracts - 5th Aspherix & CFDEM Conference 2024 in Vienna/Austria. DOI:  10.3217/978-3-99161-020-5

  • Niemann, M., Heinrich D. (2024): Liquid-gas flow around resolved densely-packed objects in CFDEMcoupling. In: Proceedings of 11th International Conference on Conveying and Handling of Particulate Solids, Edinburgh, Scotland.

Project relevant supervised students

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On the loss of contact between piles and soil during vibratory pile-driving in saturated soils (KORA)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/49-1
  • Duration/staff: 15.11.2022 to 31.12.2023 (13,5 months), 16.04.2024 to 28.02.2025 (Mechthild Cramer, 10,5 months)
  • Status: Ongoing project

Project description

Vibratory pile driving is a tried and tested method for driving piles into the ground quickly and economically. Compared to other methods, vibratory pile driving is a relatively low-vibration and low-noise driving method. Current investigations show insufficient agreement with the observations and interpretations of corresponding experiments. A cavity can form under the pile base during the upward movement. The nature of this presumed cavity is not fully understood. In addition, the separation between pore water and soil particles and a possible phase transition of the pore water to water vapour (cavitation) due to the negative pressure has not been sufficiently researched. The cavitation pressure required for this is achieved when the pore water cannot flow into the cavity quickly enough due to the permeability of the soil. The main objective of the research project is therefore to clarify the processes at the pile base during the upward movement during vibratory driving and the influence of the installation process on the subsequent static load-bearing behaviour. A further aim is to investigate the influence of physical cavitation and the presumed cavity under the pile toe during vibratory driving. Computer simulations are carried out for this purpose, which are validated with the aid of physical modelling (1g model tests).

Project relevant publications

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  •  …

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Closed-loop control of a nonlinear vibrator-profile system penetrating a heterogeneous ground (VibroSys)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/50-1
  • Duration: 01.12.2021 to 31.12.2022, pause, 01.01.2025 to 30.11.2027 (36 months)
  • Staff: Francisco Williams Riquer
  • Status: Ongoing project (project until) 31.12.2024

Project description

The aim of this research project is to develop a non-linear controller to optimize the vibratory pile driving process in order to minimize the installation time and the vibrations transmitted to the environment. For this purpose, a simplified non-linear mechanical model is developed and simulated, which describes the interaction between vibrator-pile-soil. A controller is derived from the simplified mechanical model and tested in the simulation. The construction of an experimental set-up that maps the vibration pile driving process is planned. The derived controller will be tested for different soil conditions and pile profiles in the test setup. Numerical simulations will then be carried out to check the transferability of the model results to real scenarios, taking into account an additional degree of freedom for controlling the eccentric moment.

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Future of tidal Elbe in a changing climate - climate change and flood protection (TideelbeKlima)

Status: 25.11.2024
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General data

Project description

Against the background of the effects of climate change, the joint project TideelbeKlima aims to identify and analyse the conceivable options for future flood protection in the tidally influenced area of the Elbe. It will evaluate them comparatively from a hydraulic engineering, geotechnical, water management, ecological and economic perspective. Based on the evaluation, the project will then derive options for action for the future. As the largest German tidal estuary with the city of Hamburg and the adjacent Hamburg metropolitan region, the Tidal Elbe was selected for the investigations as an example for other German tidal estuaries.

In geotechnical engineering, experimental, mathematical and numerical methods are used to determine the deformation and stability of structures. New findings are derived from the interaction of the methods and empirically verified through application and observation. Mathematical Optimization with Evolutionary Algorithms (MOEA) is used to optimize flood protection facilities.

 

Project domain. The study area corresponds to the areas at risk of flooding in the area of the tidal Elbe (image source: Institut für Wasserbau, TUHH)

Project relevant publications

  • Cerek K., Hadjiloo E., Grabe J. (2023): Sustainable dike adaption measures using finite element method and optimization algorithms NSGA-II. In: Proceedings of 5th International Conference on Geotechnics for Sistainable Infrastructure Development 2023 in Hanoi/Vietnam, Phung Duc Long, Nguyen Tien Dung (eds.), Construction Publishing House, pp. 262 (abstract)
  • Cerek K. and J. Grabe (2023): Numerical simulation and optimization of dike geometry using multi-objective evolutionary algorithm NSGA-II. In: Proceedings of 10th European Conference on Numerical Methods in Geotechnical Engineering 2023 in London/UK, DOI: 10.53243/NUMGE2023-80

Project relevant supervised students

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Optimized control of installation processes in spatially varying subsoil

Status: 02.01.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH)
  • Duration: 01.01.2022 to 31.12.2022 (12 months)
  • Staff: Philip Zirfaß
  • Status: Project cancelled

Project description

The aim of the research project was to develop methods for the optimized control of construction processes in spatially varying subsoil. The focus was on the multi-criteria optimization of the construction process in terms of construction time, construction costs and production quality. In addition, the aim was to develop methods for controlling an autonomous construction site on which both the manufacturing processes and the optimization of these run autonomously on the basis of the existing subsoil. The practical suitability of these methods was then tested using a model construction site.

Project relevant supervised students

  • J. S. (2022): Prozessorientierte Analyse der Herstellung geotextilummantelter Sandsäulen an einem Fallbeispiel. Bachelor thesis
  • F. P. & L. S. (2022): Prozessorientierte Analyse der Herstellung von Stabilisierungssäulen an einem Fallbeispiel. Bachelor thesis

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Investigation of functionalized particles

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 2462 “Processes in natural and technical particle-fluid systems (PintPFS)”
  • Duration: 01.03.2022 to 31.02.2025 (36 months)
  • Staff: Clara Toffoli
  • Status: Ongoing project

Project description

Soil is a natural particle-fluid system (PFS) in which complex physical, chemical and biological processes, interfacial phenomena and phase transitions occur that are insufficiently investigated experimentally, understood and numerically modelled. In technical PFS, certain properties of the particles are created by controlled physical, chemical and biological processes, interfacial phenomena and phase transitions (e.g. functionalized particles). Here, too, there is a need for research into understanding, modelling, and process optimization. The issues in natural and technical PFS are partly analogous. It therefore makes sense to conduct interdisciplinary research into processes in natural and technical PFS in order to gain knowledge on both sides.

Through cooperation with strategic partners and the facilities available at the TUHH, such as electron microscopy, processes are to be visualised over several length scales. Process models and numerical simulation methods used by the participating researchers will help to better understand and describe complex processes. New findings in interdisciplinary methodology are expected from the collaboration. A research training group provides the ideal framework for this. Scientists from the fields of civil engineering, mechanical engineering and process engineering will pool their research on the key topic of ‘Processes in natural and technical particle-fluid systems’ (PintPFS). The existing expertise and resources of the participating scientists with regard to experimental investigations and modelling/simulation of PFS enable an interdisciplinary research approach, which is expected to lead to innovations in the following areas in particular: Progress in the modelling of PFS, gaining an understanding of capillary effects, modelling erosion, transport and sedimentation processes, developing functionalised particles and developing numerical experiments for PFS.

The third focus of the joint project is on particles and PFS that are prepared using technical processes so that they fulfil a specific function. This applies equally to the functionalised particles already known in process engineering and to the ideas for using such particles in civil and mechanical engineering. Functional granulates, mesoporous materials such as silicates, powders made from silicate grains, aerogel particles, nanoporous powders and solids, functionalized binders and functionalized soil particles are being investigated.

Projekterelevante Publikationen

  • Magalhães Toffoli C., Milatz M., Moosmann J., Jentschke T. and F. Beckmann (2024): Synchrotrom CT images of hydrophobic sand: 1. wetting via droplet condensation and 2. water drop penetration time test. Dataset am Deutschen Elektronen-Synchrotron (DESY), Licence: Creative Commons BY, DOI: 10.15480/882.8774
  • Magalhães Toffoli C., Milatz M., Grabe J. (2023): Investigation of coated hydrophobic granular materials by means of computed tomography and environmental scanning electron microscopy. In: Proceedings of 8th International Symposium on Deformation Characteristics of Geomaterials 2023 in Porto (IS-PORTO), E3S Web of Conferences, Vol. 544, No. 07003, DOI: 10.1051/e3sconf/202454406001
  • Magalhães Toffoli C., Milatz M. and J. Grabe (2023): On the resistance of hydrophobic soil polymer coatings created by cold plasma polymerization. In: Proceedings of 8th International Conference on Unsaturated Soils 2023 in Milos/Greece, E3S Web of Conferences 382, No. 18003, DOI: 10.1051/e3sconf/202338218003

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Investigation of erosion processes at the soil-water interface and inside soil

Status: 02.01.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), Research Training Group GRK 2462 “Processes in natural and technical particle-fluid systems (PintPFS)”
  • Duration: 16.05.2022 to 31.12.2023
  • Staff: Hannah Kaiser
  • Status: Project cancelled

Project description

Due to climate change, flooding is occurring more and more frequently. As a result, water retention structures such as sheet pile walls or dykes are exposed to increased loads. In addition to the main risk of flooding, material transport in the soil and at the interface between water and soil is a key factor for the stability and serviceability of these structures.

Retrogressive erosion is a special form of internal erosion that poses a threat to the stability of structures with flow under or through them, such as dykes, weirs, and sluices. Possible damage caused by internal erosion is usually countered by design, for example by using filters or interrupting the flow, as this cannot be calculated. Material transport takes place in tubular ‘cavities’ (channels or pipes). The process is known as retrogressive erosion, as the channels form in the opposite direction to the flow of the water. Erosion begins at the downstream end of the structure and spreads against the direction of flow in a channel in the ground, between the ground and the structure or at the boundary between layers. Various processes take place during progressive erosion, as described below for a dyke. Initially, small particles move in very small channels (suffusion). When the channel reaches the upstream end, the widening process starts and when this in turn reaches the upstream end, the material transport volumes and thus the flow velocity increase. This leads to the failure of the dyke.

For a better understanding of the mechanical and hydraulic processes of erosion processes, Computed Tomography (CT) as an imaging technique offers the possibility of non-destructive examination of the interior of soil samples. For the numerical simulation of erosion processes, multiscale approaches such as CFD-DEM coupling offer visualization at particle level.

 

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Smart Vibrodriving - SMARTVIB

Status: 25.11.2025
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General data

Project description

This project endeavours to establish an advanced control system designed to facilitate the automated adjustment of feed parameters in mechanical vibrators for pile installation. Presently, these parameters necessitate manual selection and adjustment by the operator, resulting in potential delays and hindered progress in driving piles into the ground, accompanied by the transmission of vibrations to the surrounding environment. To address these challenges, our project will undertake comprehensive simulations, employing them as a basis for developing an optimized controller. Subsequently, rigorous testing will be conducted on a dedicated test stand, featuring a miniaturized vibro driver. Moreover, field measurements will be performed, utilizing authentic vibrators, in order to validate the effectiveness and practicality of our proposed solution.

Project relevant publications

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Project relevant supervised students

  • Pulido Guerrero (2022): Multi-body Simulation MBS in Matlab/Simulink of the Vibrodriving process and a fuzzy logic controller implementation to reduce the installation time
  • J. Beisner (2022): Development and automatic control of a scaled-down pile vibrator

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Adhesion between flat steel surfaces and cohesive soils (ASBO)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG)
  • Duration: 01.04.2023 to 31.03.206 (subproject testing), 01.08.2023-31.07.2026 (subproject numerical simulation)
  • Staff: Maximilian Schröder (subproject testing) and Megha Surya Narayanan (subproject numerical simulation)
  • Status: Ongoing project

Project description

An in-depth understanding of the contact surface between a structure or tool and the surrounding soil is fundamental for many geotechnical applications. Applications range from pile structures, which mobilize their load-bearing capacity via their shell surface, to tunnelling shields of tunnel boring machines, whose tunnelling performance is significantly characterized by the conditions in the interface with the ground. In most geotechnical applications, the Mohr-Coulomb friction law is used to describe the interaction between soil and structural surface. This approach works well for cohesionless soils, but for cohesive soils the behaviour at the interface is much more complex. There is adhesion and bonding of the material, and there appear to be forces in the interface that are not simply due to friction.

To date, there is no satisfactory model that can fully represent the behaviour between a steel surface and a cohesive soil. One of the aims of this research project is to create a test database that allows models of the interface behaviour between cohesive soils and steel to be derived. This is based on an extensive test programme with specialized test technology and controlled sample production. Based on the findings, numerical modelling approaches for the interface will be developed. The models developed can be applied to many geotechnical problems. Examples include tension piles in cohesive soils and adhesion phenomena occurring during mechanized tunnelling. The consideration of adhesion can lead to a more economical design and the opportunity of simulating adhesion could make it possible to better predict bonding on tools depending on the soil conditions.

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Capillary collapse in unsaturated soils (KAKO)

Status: 25.11.2024

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General Information

  • Funding: German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)
  • Duration: 01.10.2023-30.09.2026 (36 months)
  • Staff: Luisa Fernanda Pérez Jaimes
  • Status: Ongoing project

Project description

The capillary collapse is an irreversible volume reduction of partially saturated soils caused by provision of water at essentially unchanging total vertical stress. The cause of this phenomenon is probably, among other factors, the increasing dissolution of the capillary bridges, which is accompanied by a reduction in the stabilizing capillary cohesion and ultimately leads to rearrangements of the grain structure. Loosely bedded, fine-grained soils with a metastable microstructure are particularly at risk in this context. So far, existing studies on capillary collapse focus mainly on the macroscopic investigation, which is why the processes occurring on the microscale are still poorly understood. Within the framework of this research project, a better understanding of the physical processes occurring in granular media during capillary collapse on the particle scale is therefore to be gained. For this purpose, three different model soils, which show an increasing degree of complexity due to deviations from the simplest, idealized particle mixture (spherical particles with homogeneous density and uniform size), will be investigated. The starting point of the investigations is a polydisperse packing of industrially manufactured glass beads. In the next step, a model soil of natural, randomly shaped sand particles is investigated. The starting point of the investigations is a polydisperse packing of industrially manufactured glass beads. In the next step, a model soil of natural, randomly shaped sand particles is investigated. Since dump soils from opencast lignite mining are among the most endangered soils in Germany, another model soil will be investigated that contains lignite particles naturally occurring in opencast mine dump soils in addition to the sand grains as an example of a special particle structure (microporosity). In situ CT experiments with the help of the three-dimensional image data recorded over time allow insights into the processes taking place at the micro level as well as an analysis of the particle movements, whereby the knowledge gained can contribute significantly to the development of a deeper understanding of the collapse processes during saturation. Microscopic changes, e.g. in the phase distribution and capillary menisci, can be recorded and the relation to the occurring macroscopic collapse deformations can be analysed. In the planned macroscopic and microscopic experiments, the influence of various boundary conditions such as the applied vertical stress, the lignite content, the irrigation rate and irrigation direction or the matric suction present in the soil will be quantitatively investigated.

 

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Load-bearing behaviour and interaction behaviour of wet mortar columns and granular load transfer layers in combined systems (TINA)

Status: 25.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG)
  • Duration: 01.11.2023 to 31.10.2025 (24 months)
  • Staff: Pauline Kaminski
  • Status: Ongoing project

Project description

Stabilization columns, i.e. hydraulically bonded columns used for ground improvement, are a comparatively new construction method in Germany. A significant difference between stabilization columns and conventional pile foundations is the load transfer layer (LTS) above the columns. The columns, the soil between the columns and the LTS interact and form a combined system that determines the load-bearing behaviour. The research project focusses on the wet-mortar column type. Wet mortar columns are produced by concreting using the contractor method after the drill has been sunk using the partial or full displacement method. The diameter of the columns is usually approx. 20 to 40 cm. They are produced in a uniform grid with a centre distance of 3D to 5D.

The load-bearing behaviour of the combined system is not yet fully understood, and the models on which the design is based are based on highly simplified approaches. The influence of a change in the soil condition variables due to the grid-shaped installation process has not yet been quantified. Furthermore, the influence of cyclic loads on the load transfer and the vault effect in the LTS has not been sufficiently researched

The main objective of the research project is to clarify the load-bearing behaviour of combined systems, taking into account

  • manufacturing influences,
  • the group effect,
  • and the interaction between soil, column, load transfer layer and foundation using the example of wet mortar columns and granular load transfer layers with statically monotonic and cyclically occurring loads. 

For this purpose, numerical simulations are carried out, which are supplemented and validated by means of physical modelling (1g model tests). Continuum models are used for the numerical calculations. The corresponding equations are solved using the Finite Element Method (FEM). The Coupled Eulerian-Lagrangian (CEL) approach, which has proven itself in the preliminary investigations for the simulation of the drilling process, is used for this purpose.

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Virtual Soil Laboratory

Status: 25.11.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH), Poolstelle
  • Duration: 01.02.2024 to 31.01.2028 (48 months)
  • Staff: Mohamed Ali Abdennadher
  • Status: Ongoing project

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Strengthening and optimization of quay walls

Status: 22.11.2024
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General data

  • Funding: Technische Universität Hamburg (TUHH), Promotionsförderungsstelle
  • Duration: 01.10.2024 to 31.03.2028
  • Staff: Daniel Tetla
  • Status: Ongoing project

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port:Evolution - Data mining of infrastructure inventory data, process automation, and improvement of 3D scans for the fully automated digital twin of harbour structures - sub-project model improvement of quay walls

Status: 22.11.2024
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General data

  • Funding: Bundesministerium für Digitales und Verkehr (BMDV)
  • Project management: TÜV Rheinland, FKZ 19H24001F
  • Duration: 01.12.2024 to 30.11.2027 (36 months)
  • Staff: Kacper Cerek
  • Status: Project start at 01.12.2024

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Load-bearing bahaviour of tension piles (TensionPI)

Status: 22.11.2024
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General data

  • Funding: Deutsche Forschungsgemeinschaft (DFG), project GR 1024/64-1
  • Duration: 01.01.2025 to 31.12.2027 (36 months)
  • Staff: Lennart Sekulic
  • Status: Ongoing project

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