Three-Dimensional Discrete Element Method of Analysis of Clays

Discrete element method is an ideal numerical technique for studying the constitutive behavior of not only granular materials, but also cohesive materials such as a clayey soil. Presented in this paper is a three-dimensional discrete element method for modeling the behavior of saturated clays. In addition to the mechanical interactions as between two granular particles, there are physico-chemical interactions between two clay particles. Two primary physico-chemical forces are the van der Waals attractive force and the double-layer repulsive force. Furthermore, unlike granular soils, which are bulky, clay particles are plate like. In the present study, a three-dimensional discrete element method is developed and used to conduct one-dimensional compression of an assembly of particles and some results are presented and discussed. Micromechanical methods such as the discrete element method (DEM) are very useful in studying the fundamentals of the stress-strain behavior of clayey soils. Proposed originally by Cundall and Strack to analyze a collection of granular particles, the method has since been used to study many other types of discrete, and in some cases continuum, materials. Anandarajah developed a two-dimensional discrete element method for the analysis of clays, where particles were approximated by rectangles. Procedures have been developed in recent years to quantify the physico-chemical forces between clay particles, which were used in the two dimensional studies. A more realistic simulation requires a three-dimensional analysis methodology, and this is achieved in the present paper.