Macroscopic and microscopic analysis of particle flow in direct shear mechanical characteristics of rock structural surface

Abstract

 At present,the roughness resulting from the random distribution of particle sizes and positions causes the phenomenon that stress concentration occurs in the simulation process,making it impossible to simulate the shear behavior of structural surfaces of rocks accurately when we use PFC2D in numerical simulation.In order to avoid this defect,we use the method of particle group contact discrimination on both sides of the structural surface to respectively simulate the direct shear simulation of the triangular single serrated structural surfaces with inclination angles of 20 degress and 30 degress under distinct normal stresses.The result is consistent with the experimental result basically,demonstrating that this simulation method can truly simulate the shear behavior of rock structural surfaces of rocks.In order to further verify the feasibility of this simulation method in the simulation test of natural structural planes,we use PFC2D to conduct direct shear tests on the ten-standard-joint profiles model proposed by Barton under different normal stresses.The simulation result is consistent with the theoretical values,suggesting that the simulation method is feasible to provide a reliable theoretical basis for the shear failure process and mechanism analysis and to provide a way of thinking for the study of the strength characteristics of rough structural surfaces of rocks.