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 e_min and e_max 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

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

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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

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

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 and for separation of soil constituents

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