Simulation of Triaxial Tests for Unsaturated Soils under a Tension–Shear State by the Discrete Element Method

Abstract

In this paper, the discrete element method is used to simulate triaxial tests of unsaturated soil under a tension–shear state. A relationship between water content and uniaxial tensile strength with different void ratios is obtained, which is applied to uniaxial tensile discrete element simulations to establish a relationship between grain-scale parameters and water content from back analysis. A group of triaxial simulations for unsaturated soil under a tension–shear state is then conducted. The discrete element method is used to obtain the relationship between deviatoric stress and axial displacement with different water contents, and also to reveal the effects of water content on peak strength and dilatancy phenomena with different confining pressures. The displacement fields of numerical specimen are analyzed qualitatively, and the mechanism and process of failure are discussed from the prospective of energy and dissipation.