Simulation of Brittle Rock Failure Using 2D Continuum-Based Voronoi Tessellated Models

Abstract

Micro-structural heterogeneities of brittle rocks govern their failure process, which involves crack initiation and propagation before the peak stress is reached. Voronoi tessellation is an approach, commonly used in discontinuum numerical programs to simulate brittle rocks by dividing the numerical specimen into several randomly generated polygonal blocks. In this study, a 2D Voronoi Tessellated Model (VTM) is developed in a continuum program to simulate the behavior of Lac du Bonnet (LdB) granite. The VTM is first calibrated to the laboratory properties of LdB granite. The calibrated VTM captures the damage evolution and failure mode transition from axial splitting to shear failure with increasing confinement. Next, v-shaped notch failure around a circular test tunnel is simulated by the VTM calibrated to the rock mass strength estimated based on the s-shaped failure criterion. It is concluded that the calibrated VTM realistically simulates the observed failure and damage zones around the tunnel.