Modeling the direct shear test of a coarse sand using the 3D Discrete Element Method with a rolling friction model

Abstract

In this research, a direct shear test was modeled using the 3D Discrete Element Method (DEM). The results are compared against experimental data. The real sand was modeled as about 70,000 spheres, with sizes consistent with the real grain size distribution, using a rolling friction model to include the sand's grain shape. It is shown that, the stress path can be appropriately reproduced, but the dilatancy were very difficult to replicate. Finally, specimens with up-scaled material were tested. Although the unscaled material was the most representative, the response of the particles that were up-scaled twice was slightly less accurate, but with a considerable decrease of computation time.