On the way to a digital soil lab: Linking geomechanical X-ray CT experiments and numerical modelling on the grain scale

Abstract In this four-page contribution, we briefly present experimental research on the shear behaviour of granular materials by means of miniaturised direct shear tests which are run in a CT scanning environment. The acquisition of 3D CT data during direct shearing allows to study grain kinematics of sheared granular materials and the hydro-mechanical coupling of grain motion and pore fluid morphologies in the unsaturated state. Besides selected experimental insights, we discuss discrete numerical simulations of the direct shear test by means of the Finite-Discrete Element Method (FDEM). This method allows to consider FE meshed sand grains with quasi-natural shapes based on CT data and to model their interactions in particle scale discrete element simulations.