Damage and Failure of Hard Rocks Under True Triaxial Compression

Abstract

To reveal the effect of intermediate principal stress on the damage and failure of hard rocks, the failure evolution of hard rocks under true triaxial compression is reviewed, based on the previous study. From the viewpoint of crack growth under true triaxial compression, different fracture evolution stages of hard rocks, including the elastic stage, stable growth stage, and unstable growth stage, are introduced. Additionally, the effect of the intermediate principal stress on the crack stress thresholds is summarized. It is found that as the intermediate principal stress increases, its effect will first restrict and then promote crack propagation. The energy evolution of the rock cracking process under true triaxial compression is also analyzed. The damage evolution is quantified by damage