Investigations of micro-structure evolution in granular shear zones using DEM

The evolution of shear zones in initially medium dense cohesionless sand for quasistatic earth pressure problems of a retaining wall was analysed with a 3D discrete element method DEM using spheres with contact moments. The passive sand failure for a very rough retaining wall undergoing horizontal translation was discussed. Attention was laid on some micro-structural events appearing in shear zones (force chains, vortex structures, local density fluctuations). The calculated geometry of shear zones was compared with experimental results of laboratory model tests and finite element calculations.