3D DEM Simulation on the Reliquefaction Behavior of Sand Considering the Effect of Reconsolidation Degree
Teng Zhao, Jianhong Ye
Abstract
More and more earthquake cases demonstrate that sandy deposits may be more prone to becoming liquefied again in aftershock events. This phenomenon has also been authenticated by some laboratory element tests and shaking table tests. However, most of the existing studies on reliquefaction only put particular emphasis on the completely reconsolidated soil. Due to the possible short time interval between the main shock and its aftershock events, the generated pore pressure in soil deposits may not have completely dissipated when the aftershock occurred; the reliquefaction is more likely to occur under incomplete consolidation conditions. To investigate the reliquefaction behaviors and the related microscopic mechanisms for the incompletely and completely reconsolidated soil, a series of numerical cyclic triaxial tests are performed in this study via the 3D Discrete Element Method (DEM). Results demonstrated that the reliquefaction resistance of soil is significantly affected by the residual strain and the reconsolidation degree. From the microscopic point of view, the fabric anisotropy and the tightness of inter-particle contacts are the main factors affecting the reliquefaction resistance.