Simulation on Mechanical Behavior of Cohesive Soil by Distinct Element Method

摘要

The mechanical microstructure of cohesive soil was analyzed, and the discrete pendular liquid bridges formed by interstitial water in cohesive soil, which produce the capillary and the dynamic viscous forces between soil particles, was pointed out. This is one of the main factors that soil possesses cohesion. Based on the capillary and the dynamic viscous forces induced by the presence of water, along with taking into account the contact forces and the forces of friction between soil particles, the Distinct Element Method (DEM) mechanical model of cohesive soil was established. The mechanical behavior of cohesive soil was simulated by DEM special software PFC2D~®. The results indicated that the parallel bonds of the simulated cohesive soils make the discrete particles bond into clusters. Then these clusters break down into smaller clusters or discrete particles during the process of the interaction between the bulldozing plate and cohesive soils. The phenomena are very similar to the real cohesive soils subjected to external forces. The establishment of the DEM mechanical model of cohesive soil and the dynamic simulation of the interaction between the bulldozing plate and cohesive soils are very important in predicting the mechanical behavior of these soils accurately and optimizing the soil-tool interaction.