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地下结构中广泛存在的各种不连续面是影响岩体工程力学特性的重要因素,研究结构面在循环荷载作用下的力学行为具有重要的工程意义。基于非关联塑性理论,同时定义加载剪胀段和反向剪缩段,建立了岩体结构面剪胀与塑性耦合本构关系;从结构面的基本损伤机制出发,基于拉、剪分离的思路,建立了一类基于能量原理的岩体结构面拉、剪损伤本构模型,该模型基于有效应力空间塑性力学基本原理,定义了岩体结构面拉、剪塑性Helmholtz自由能分量及损伤能释放率,建立了岩体结构面拉、剪损伤破坏准则。针对结构面在循环荷载作用下的强非线性问题,引入算子分解的思想,将弹塑性演化与损伤演化过程分开进行求解,提出了结构面弹塑性损伤本构关系的混合积分算法。分别进行了岩体结构面直剪和循环剪切试验的数值仿真,计算结果与模型试验基本一致,表明该模型在模拟非连续岩体复杂变形方面是合理有效的。
The various discontinuities that exist extensively in underground structures are important factors that affect the mechanical properties of rock mass engineering. It is of great engineering significance to study the mechanical behavior of structural plane under cyclic loading. Based on the non-associative plasticity theory, the dilatancy section and the reverse shear section are defined at the same time to establish the dilatancy and plastic coupling constitutive relationship of rock mass structural plane. Based on the basic damage mechanism of the structural plane, , A constitutive model of tension and shear damage of rock mass structural plane based on energy principle is established. Based on the basic principle of plastic mechanics of effective stress space, the model defines the Helmholtz free energy component and damage energy release Rate, the establishment of rock structure pull, shear injury damage criteria. Aiming at the strong nonlinear problem of the structural plane under cyclic loading, the idea of operator decomposition is introduced to solve the elastoplastic evolution and the damage evolution process separately. A hybrid integral algorithm for elastoplastic damage constitutive relation is proposed. The numerical simulations of direct shear tests and cyclic shear tests on the rock mass discontinuities are carried out respectively. The calculated results are basically consistent with those of the model tests, which show that the model is reasonable and effective in simulating the complex deformation of discontinuous rock mass.