以热力学和弹塑性力学理论为基础,分析岩石热-力完全耦合作用及其对力学参数和热特性参数的影响,建立了岩石热-力-损伤耦合模型及其参数演化方程,以ABAQUS软件为平台对其进行二次开发,并通过典型算例验证了岩石热-力完全耦合的重要性。然后以某深埋软岩隧洞为例,研究温度和开挖卸载共同作用下的隧洞围岩力学行为和损伤过程。计算结果表明:温度对岩石的力学性质和损伤演化过程影响显著,开挖损伤和热应力诱发的损伤对围岩热力学参数的影响不可忽略;所提出的力学模型可以有效反映围岩损伤演化、调热圈演化以及热力学参数演化,具有一定的借鉴作用。
Based on the theories of thermo-mechanics and elastoplastic mechanics, the thermo-mechanical coupling effects of rock and their effects on mechanical and thermal parameters are analyzed. By defining the evolution equations of thermo-mechanical coupling parameters under the damage of temperature effects and mechanics, a new coupled thermo-mechanical damage model with improved Mohr-Coulomb criterion is established, and the numerical implementation in ABAQUS is given. Using finite element method, a typical example was given to verify the importance of the thermo-mechanical fully coupling of rock. Taking a deep tunnel of clay stone as background, the evolution and distribution of damage, temperature and coupling parameters of the surrounding rock are simulated in detail. The results show that the temperature has a great influence on rock properties and damage evolution. Also, the damage by excavation and thermal stress has a great influence on conducting and diffusing of heat. The proposed model can depict the excavation damage, control heat circle and coupling parameters evolution, and may provide a new tool for associated applications.