To investigate crack initiation and propagation of rock mass under coupled thermo-mechanical (TM) condition, a two-dimensional coupled TM model based on the numerical manifold method (NMM) is proposed, considering the effect of thermal damage on the rock physical properties and stress on the heat conductivity. Then, the NMM, using empirical strength criteria as the crack propagation critical criterion and physical cover as the minimum failure element, was extended for cracking process simulation. Furthermore, a high-order cover function was used to improve the calculation accuracy of stress. Therefore, the proposed method consists of three parts and has a high accuracy for simulating the cracking process in the rock mass under the coupled TM condition. The ability of the proposed model for high accuracy stress, crack propagation, and thermally-induced cracking simulation was verified by three examples. Finally, the proposed method was applied to simulate the stability of a hypothetical nuclear waste repository. Based on the outcome of this study, the application of NMM can be extended to study rock failure induced by multi-field coupling effect in geo-materials.
Timeliness of collinear crack propagation in rock mass
