Influence of inherent anisotropy on the soil behavior in simple shear tests using DEM

Abstract

The discrete element method was adopted in this paper to numerically investigate the macroscopic behaviors of granular material with initial anisotropic fabric in simple shear tests. The evolutions of the stress-strain relationship, the non-coaxiality referring to the difference of principle directions between the strain rate and the stress increment, and the fabric anisotropy were analyzed during the tests. The results indicated that inherent anisotropy affects the shear strength. The directions of principal strain rate and principal stress are non-coaxial at the start of the shear loading and they become coaxial gradually as the shear strain increases. Both the principle directions of particle orientation and contact normal change towards 45°, but the later is much faster than the other.