Modeling of montmorillonite clay-water interactions with particle subdivisions using three-dimensional discrete element method.

摘要

Montmorillonite clay is an expansive clay which undergoes large volumetric changes with the change in its water content. This is both beneficial and problematic. The behavior of clay depends on its microstructural properties such as mineral constituents, pore fluid chemistry, particle arrangement and void ratio. At the macroscopic level there are typically two major force groups, namely mechanical forces (gravity, contact, friction and interlocking forces) and physicochemical forces (double layer, van der Waals and Born's repulsion forces).; A better understanding of montmorillonite clay behavior as well as its interaction with different solvents is necessary. Several researchers have attempted to correlate clay microstructure to its properties in an attempt to explain some of the complex clay behaviors. Studying clay behavior at the macro scale level can be conducted to some extent experimentally using Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Clay behavior and mechanisms can be studied numerically using numerical methods such as Finite Element Method (FEM) and Discrete Element Method (DEM).; DEM was used to study the behavior of soil particles such as sand and clay under different conditions. Microstructural properties like particle subdivision and some interparticle forces were either totally ignored or extremely simplified in previous studies. In the present research, the DEM simulates particle subdivision for the first time. In this work, a three dimensional DEM technique with particle subdivision was developed, the software for the technique was created, and simulations were conducted to evaluate quantitatively the role of particle subdivision on swelling and swelling pressure characteristics of montmorillonite.