In order to better revealed the shear characteristics and mechanical behavior of soil-rock mixture, three samples of indoor mixtures with different rock contents were selected for the studied of the core wall material of a soil-rock dam in Bole District, Xinjiang, by importing the random polyhedron templates to build real block particles, and the different content of rock under different confining pressure of large direct shear test simulation of soil-rock-mixture PFC3D stone content in the sample shear strength was studied, the influence of soil-rock-mixture was analyzed in the process of shearing force of soil-rock-mixture volume change and chain distribution network. The results show that the fitting degree between simulation results and laboratory tests was good, they had good consistency. The higher content of rock, the greater the shear strength of soil-rock mixture. Under the same normal stress, the dilatancy of the sample increases with the increase of the rock content, the low rock content is the softening characteristic, and the high rock content is the hardening characteristic. With the increase of rock content, the number of strong chains increases, the distribution becomed more concentrated, and the overall stability is relatively stable. The soil-rock mixture shows higher shear strength macroscopically. This studied could better understand the micromechanical mechanism of soil-rock mixture and provided reference for the relevant rock-soil mechanical simulation.
