Numerical simulation of pore fluid characteristic effect on the volume change behavior of montmorillonite clays

The aim of this paper is to analyze the association between the volume change in clayey sealing materials and pore fluid chemistry under different stresses. Montmorillonite is considered because it is commonly used as a barrier in geo-environmental projects. Microscopic observations are numerically simulated using a discrete element method (DEM). A DEM code has been developed by considering both mechanical and diffuse double layer repulsion as interparticle interactions. The results show that volume change behavior is strongly influenced by the type of the electrolyte and its concentration. An increase in the valance of exchangeable cation and electrolyte concentration cause a reduction in the thickness of DDL and soil compressibility. The DEM simulations are compared with theoretical and experimental data, and their agreements are reported. It is concluded that DEM is a virtual laboratory for simulating the microstructural behavior of clay.