Fracture evolution of transversely isotropic rocks with a pre-existing flaw under compression tests based on moment tensor analysis

A numerical approach based on the particle discrete element theory is adopted to study the fracture evolution of transversely isotropic rocks with a pre-existing flaw under compression tests. In this approach, the rock matrix is simulated by parallel-bonded contacts and weak planes are represented as bonded contacts, and the acoustic emission characteristics of rock matrix and weak planes are obtained and distinguished using the moment tensor analysis. Firstly, the acoustic emission features of the numerical approach were validated against the test results. Then, parametrical studies were conducted to reveal the combined effect of pre-existing flaw and weak planes on the fracturing morphology of rocks, and six failure patterns were identified. Finally, the fracturing evolution process of each pattern was studied based on the moment tensor analysis.