Study on Shear Fracture Characteristics of Coarse Grained Soil Based on DEM-FDM

Based on the laboratory triaxial test of coarse-grained soil, the discrete element method (DEM) in two dimension was used to conduct the biaxial test model, and the microscopic parameters and deformation characteristics of coarse grained soil were obtained. Under the premise of more apt numerical and experimental results, the same parameters were set in FLAC3D which is based on finite difference method (FDM) to analyze the changes of local stress in the compression process of the sample, so as to find out the shear fracture. Comparison of the fracture zone obtained from PFC2D and FLAC3D was also made. The results show that the stress-strain curve obtained by the DEM is in good agreement with the laboratory results, and the strain softening phenomenon occurs. Based on the same microscopic parameters, the shear fracture generated in the PFC2D model can roughly coincide with the maximum stress fracture in the FLAC3D model.