An upgraded CFD-DEM investigation on the liquefaction mechanism of sand under cyclic loads

Abstract

A CFD-DEM scheme is utilized to investigate the mechanical behavior of saturated sand under cyclic loads. The CFD-DEM scheme is upgraded by taking into account the influence of Magnus force, which acts on spinning particles in fluid. The bond contact model that can consider the slight plastic deformation of particles during collisions is also adopted to effectively dissipate the kenetic energy. A series of cyclic triaxial tests are simulated and results showed that, for the stress-strain relationship, the area of hysteresis loop increases with the increasing confining pressure, indicating that the plastic dissipation energy increases during the cyclic loading. The microscopic mechanical response of sand are analyzed with regard to the velocity field, combine which the analysis of contact force can partly shed light on the liquefaction mechanism.