DEM simulation of creep in one-dimensional compression of crushable sand

Abstract

Particle-scale mechanisms that control the static creep behavior of crushable sands are not well understood. In this context, this study examines the problem of creep of crushable sands undergoing one-dimensional (1D) compression by using a three-dimensional (3D) discrete element method (DEM) simulation. The rate process theory (RPT)-based creep contact model considering rolling resistance and a probabilistic particle fracture model satisfying mass conservation were incorporated into a large-scale DEM simulation. The coupled effects of the interparticle sliding and delayed particle fracture and the influences of rolling resistance, initial porosity, and characteristic particle strength on the creep behavior were then investigated. The high capabilities of the model in reproducing many facets of the soil behavior during the 1D compression and creep seen in the laboratory was demonstrated by comparing the simulation results with published experimental data. It was found that the creep deformation was mainly caused by stress redistribution at low vertical stress while particle rearrangement and particle breakage became more prevailing with the increase of vertical stress.