GeoCheck

The aim of the GeoCheck project is to investigate, both experimentally and numerically, the influence of grain shape parameters (granulometric properties) on the results of cone penetration tests (CPT). In addition to density and the pressure on the grain skeleton, the grain shape and the initial orientation of the particles (arrangement conditions) in the soil – provided it is not heterogeneous – have a significant influence on the mechanical properties of the soil. These mechanical properties can be measured indirectly on-site using cone penetration tests. The data from cone penetration tests are interpreted and form, among other things, the basis for the geotechnical assessment of a soil; however, practical knowledge regarding the influence of granulometric properties and embedding conditions is currently lacking.

In the FTZ sub-project ‘Development of a geometric soil model to describe the geometric mechanics of cohesive and non-cohesive soils using the Discrete Element Method (DEM)’, descriptive parameters of grain shape and grain surface known from the literature are therefore to be selected. Building on this, an experimental study will be conducted in the laboratory to analyse the influence of granulometric properties in soil mechanics laboratory tests. The focus will be, in particular, on investigations to determine storage density and studies to determine strength (undrained cohesion). In parallel, a numerical model will be developed to investigate granulometric effects that are difficult to verify experimentally. To this end, existing DEM models will be extended to account for the influence of grain shape parameters, and the tests will be simulated on a reduced scale.

The experimental and numerical results will assist our project partner, Baugrundbüro Klein, in developing a mathematical-physical model for the rapid, automated calculation of geotechnical soil parameters from the tip pressure of cone penetration tests.