A DEM investigation of the shearing behaviour of non-active clays

Abstract

This paper presents the numerical DEM simulation of shear tests on two-dimensional clay-like specimens. Clay particles are modelled as rod-shaped elements made of spherical elementary units. The contact laws implemented in the adopted DEM framework account for both the mechanical interaction developing between particles in contact, and the long-range electro-chemical interaction in the form of Coulombian attraction/repulsion between charged particles. Virtual specimens for shear testing are obtained via the one-dimensional compression and unloading of clay-like particle assemblies, in order to study the effect of different over consolidation ratios on the macroscopic mechanical behaviour. The DEM framework is challenged against its ability to reproduce qualitatively key aspects of the macroscopic behaviour of normally consolidated and over consolidated clays during shearing, including contractive and dilative behaviour, and monotonic and non-monotonic stress-strain behaviour.