Numerical Simulation of Pile-Soil Interface Cyclic Weakening Effect by Particle Flow Code (PFC)

摘要

Aiming at the cyclic weakening mechanism of pile-soil interface of different interface roughness, particle clusters of different shapes are randomly created by using the cluster as an alternative to the traditional single disc to simulate the shearing interface of different roughness and establish the PFC2D constant stiffness cyclic shear model. The results show that the shear stress shows a logarithmic weakening with the increase of the number of cycles, diminished by about 30%~46%, and the weakening coefficient of shear stress ratio is between 0.10-0.16, which gradually increases with the heightened interface roughness; the thickness of shear band formed by the broken particles through cluster breakup reaction is approximately 3 to 6 times the median particle size, and the shear band thickness increases with the increase of the relative roughness of the interface.