Abstract
The shear mechanism of granular materials has been studied from a microscopic point of view in order to derive their macroscopic stress-strain relationship. For this purpose, direct shear box tests and simple shear tests were carried out using a pile of aluminium rods (or photoelastic rods) to simulate granular materials in a two-dimensional state. In the analysis, granular materials are considered to be an assembly of a unit element composed of two particles, which is named “two particles model”. According to this model, the sliding displacements between two particles across the potential sliding plane were formulated by considering the mechanism of disappearance and generation of angles of interparticle contacts. A new stress-strain equation was derived from the relationship of these sliding displacements, and compared with results of a cyclic simple shear test on aluminium rod mass. Furthermore, the proposed stress-strain relationship in a two-dimensional state was extended to that in a three-dimensional state by introducing the concept of “Spatial Mobilized Plane” (SMP), and compared with results of true triaxial tests on Toyoura sand.
