Hierarchical Modeling Method for DEM Simulation and Its Application in Soil–Pile–Cap Interaction and Impact Case

Abstract

By developing a hierarchical modeling method, using discrete element analysis software PFC3D, a discrete-element method (DEM) model can be built and solved more efficiently. In this method, smaller particles are used for the concerned part, medium-sized particles are used in the transition zone, and larger particles are used for the part that is close to the model boundary. By adjusting the micromechanical parameters of the particles through simulated triaxial tests, the macroscopic mechanical properties of the soils constituted by different-sized particles are kept consistent. This method can be applied to study the soil–structure interaction problems with the DEM method by saving computation cost. The proposed method is verified by a two-dimensional (2D) simulation of a laboratory pile load test. This method is then further applied to investigate the pile–soil–cap interaction problem focusing on the pile cap effects. A geohazard-related impact case is also analyzed using this method.