Shear–induced anisotropy in granular materials under various saturation states

Abstract

This study presents a micromechanical study on the characteristics of shear-induced anisotropy in granular media under various saturation states. A series of unsaturated triaxial compression tests under the full range of degree of saturation are performed by using Discrete Element Method (DEM). The effect of the suctions on the characteristics of anisotropy is illustrated and discussed. Good agreements between anisotropy and stress ratio are observed for saturated and unsaturated states if skeleton contact stress is adopted. With the increase of the suctions, the weight of fabric tensor anisotropy decreases while the weight of anisotropy related to normal forces increases. The mechanical anisotropy plays a dominant role in providing shear resistance for the full saturation range.