LAUSR

This paper presents the PFC/FLAC coupled method to simultaneously reveal the macro- and micro-mechanisms of granular soils during dynamic compaction. A good agreement was found between the numerical simulation and model test. By analyzing the soil displacement field, motion of tracer particles, and evolution of local porosity, the dynamic densification process of granular soils was reproduced. The results show that soil deformations under dynamic compaction can be divided into two modes: the punching deformation caused by the wedging effect of a conical core based on the bearing capacity mechanism, and the compaction deformation induced by the propagation of dynamic waves based on the densification mechanism. The dynamic compaction process is composed of two phases: compaction because of the transient impact and compaction because of the vibration of soil particles.