Experimental and DEM Study of Two Dimensional Simple Shear

It is well established that the principal stress rotation (PSR) can lead to plastic deformations in soil, and soil is subjected to two dimensional shears in many geotechnical applications, which lead to two dimensional principal stress rotations. This paper aims to study impacts of two dimensional PSRs on soil behavior by using the DEM and experimentation, in which glass beads are used. In the two directional simple shear apparatus, the first shear is exerted on samples along one direction, followed by the second shear at varying angles to the first shear. The experimental results indicate that the angle between the first and second shears have a great impact on the sample strength. The DEM results are in very good agreement with the experimental results on the development of both shear stress and volumetric change. Further, lateral normal stresses in the simple shear in the DEM study can be obtained, enabling the computation of principal stresses under two dimensional shears. Fabric developments of samples can also be studied in the DEM simulation.