Study on the mesoscopic failure process of heterogeneous rock based on the 3-D GBM model

The rock deformation and failure processes under uniaxial compression are a fundamental issue in rock mechanics. This study constructs a numerical heterogeneous rock specimen composed of Voronoi polyhedral particles using Neper software. It examines the fracture patterns, mechanical behavior, and strength of granular rock through numerical simulations using the 3-D distinct element code. The findings demonstrated that the number of cracks escalates with increasing axial stress. The rate of crack initiation rises significantly when the axial stress is approximately 57.3% of the peak stress, and shear cracks start to appear when the axial stress reaches 73.84% of the peak stress. These heterogeneous rock specimens exhibit significant axial splitting damage under uniaxial compression, transitioning from tensile to shear failure as the axial stress improves. In addition, smaller internal friction angles lead to more severe failures, and the more fully developed the shear zones are, the more pronounced the rock mass?s zonal fracturing becomes.