Research methods
Stand: 24.11.2024
Experimental soil mechanics
- Determination of grain size distribution according to DIN EN ISO 17892-4 (formerly DIN 18123)
- Determination of water content according to DIN EN ISO 17892-1 (formerly DIN 18121)
- Determination of Atterberg limits for cohesive soils according to DIN EN ISO 17892-12 (formerly DIN 18122)
- Determination of density according to DIN EN ISO 17892-2 (formerly DIN 18125)
- Determination of bulk density according to DIN EN ISO 17892-3 (formerly DIN 18124)
- Determination of emin and emax for non-cohesive soils according to DIN 18126
- Determination of lime content according to DIN 18129
- Determination of ignition loss according to DIN 18128
- Determination of water absorption capacity according to DIN 18132
- Determination of hydraulic conductivity according to DIN ISO/TS 17892-11V (formerly DIN 18130)
- Determination of Proctor density and optimal water content according to DIN 18127
- Determination of angle of repose of non-cohesive soils
- Determination of abrasivity with the abrasimeter according to ANFOR NF P 18-579
- Determination of properties of suspensions (suspension density, run-out time with the Marsh funnel, spread dimension, yield limit using spherical harp, filtrate water discharge, settling dimension in the stand cylinder)
- Determination of viscosity of fluids with the rheometer
- Permeability test with constant head
- Permeability test with falling head
- Oedometer tests (IL, CRS, creep test, swelling test, soft oedometer test)
- Direct shear tests (constant normal stress, constant volume, constant stiffness, monotonous/cyclic loading)
- Ring shear tests
- Triaxial tests including standard tests (CD, CU, UU) and a couple of special tests
- Uniaxial compression test
- Simple shear tests (monotonous/cyclic loading, constant normal stress, constant volume or constant stiffness, multiaxial shear test with continuous change of shear direction, investigation of capillarity in unsaturated soils)
- Resonant-Column Test
- Laboratory vane shear test
- Optical microscopy
- Computed Tomography (CT)
- ...
- 1g model tests
- ng model tests (centrifuge tests) in cooperation with the Centre of Offshore Foundation Systems (COFS) at University of Western Australia (UWA) in Perth
- Field tests in on a semi-industrial and prototype scale
- Measurement of displacements, strains, forces, stresses, velocities, accelerations etc.
- Measurement of dispersion waves
Laboratory tests
Classification tests
Permeability tests
Investigation of stress-strain behaviour
Determination of capillary-saturation behaviour
...
Imaging methods
Physical Modelling (model tests)
Field tests
Theoretical soil mechanics
- Multiphase-models for saturated and unsaturated soils based on continuum theories for porous media
- Development of a constitutive model for the transition of soil → concrete, required in the course of numerical optimization
- Investigation of capillarity in unsaturated soils
Computational soil mechanics
- Governing equations: Terzaghi's consolidation theory and extensions, Biot's poroelasticity and derived poroplasticity (poromechanics), mixture theories
- Numerical Methods:
- Finite Element Method (FEM) with Lagrangian approach for small to moderate soil deformation
- Finite Element Method (FEM) with Coupled Eulerian-Lagrangian (CEL) approach for large soil deformation
- Smoothed Particle Hydrodynamics (SPH) for large soil deformation and for separation of soil constituents
- Material Point Method (MPM) for large soil deformation
- Calibration of constitutive models for soils
Continuum models (macroscopic approach)
- Governing equations: Newton's equation of motion
- Numerical Method: Discrete Element Method (DEM)
Particle models (microscopic approach)
- Governing equation: Boltzmann equation
- Numerical method: Lattice-Boltzmann Method (LBM)
- Multiscale models for saturated soils based on a continuum model for the pore fluid and a particle model for the grain skeleton
- Governing equations: Field equations for the pore fluid, Newton's equations of motion for the particles, model for the momentum exchange between pore fluid and particles
- Numerical methods: CFD-DEM coupling resolved (several fluid cells per particle), CFD-DEM coupling unresolved (several particles per fluid cell)
- Multiscale models based on Boltzmann's kinetic theory for the pore fluid and particle mechanics for the grain skeleton:
- Governing equations: Boltzmann-equation for the pore fluid including a collision model, Newton's equation of motion for the particles, and a model to describe the momentum exchange between pore fluid and particles
- Numerical method: LBM-DEM coupling in cooperation with Prof. Krishna Kumar
Models based on Boltzmann's kinetic theory (mesoscopic approach)
Hybrid models (multiscale approaches)
Numerical optimization
- Numerical multi-criteria optimization in combination with numerical simulation
Conventional calculation methods
- For example. Kinematic Element Method (KEM), slope stability analysis etc.