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为了更准确、便捷地确定深埋地下工程中硬岩的力学行为,开展了如下研究:根据损伤与塑性演化存在相似机制,假设损伤阈值与初始屈服采用相同的确定方法,将岩石统一能量屈服准则作为损伤阈值的判定准则;基于Rabotnov对损伤变量的定义和Lemaitre应变等效性假设,并考虑未损伤部分的应力-应变关系符合广义虎克定律,提出了简化形式的硬岩损伤本构方程;为了更好地表达硬岩从低围压到高围压条件下的脆-延转化特性,提出了改进的Mazars损伤演化方程;基于锦屏T_(2b)大理岩常规三轴压缩试验结果,对损伤模型参数进行求解,并分别与基于Mazars损伤演化方程和Mohr-Coulomb准则为损伤阈值判定准则的损伤模型进行对比,结果表明:提出的损伤模型可更好地表达硬岩从低围压的脆性到高围压的延性转变过程,特别是对损伤阈值后岩石的损伤演化过程的模拟更为精确,对硬脆性岩石的工程计算有一定的借鉴意义。
In order to determine the mechanical behavior of hard rock in deep underground engineering more accurately and conveniently, the following research is carried out: According to the similar mechanism of damage and plastic evolution, assuming that the damage threshold and initial yield are determined by the same method, the rock uniform energy yield criterion As the criterion of damage threshold. Based on Rabotnov’s definition of damage variable and Lemaitre strain equivalence hypothesis, and considering the stress-strain relationship of unimpaired part, the simplified Hock damage constitutive equation is proposed according to generalized Hooke’s law. In order to better express the brittle-ductile behavior of hard rock from low confining pressure to high confining pressure, an improved Mazars damage evolution equation is proposed. Based on the results of conventional triaxial compression tests of Jinping T_ (2b) marble, The results show that the proposed damage model can better express the brittleness of the hard rock from the low confining pressure To the ductile transition process of high confining pressure, especially the damage evolution of rock after the damage threshold is simulated more accurately, Rock engineering calculation has some reference.