岩体-界面系统剪切不稳定性分析

基于界面的刚塑性应变软化假设，分析了岩体－界面系统在端部剪力和岩体中分布剪切载荷共同作用下的变形、应力和损伤演化。利用位能原理和稳定性的能量准则，得到了岩体界面系统的不稳定性条件。分析结果表明，损伤区达到边界之前，系统可能是稳定的或者是不稳定的。依赖于分布剪切载荷和界面摩擦力的比较，若均布剪切载荷大于界面摩擦力，则系统不稳定，否则系统稳定；当损伤区达到边界之后，系统的不稳定性决定于载荷及界面材料性质，界面软化刚度系数和界面强度对于不稳定性有明显影响。

Instability analyses of rock-interface system under shear loading

Based on the assumption of rigid|plastic and linear strain|softening interface, the deformation, stresses and damage evolution of rock|interface systems were studied under the mutual action of boundary and volume shear loads. According to the potential principle and energy criterion of stability, the shear instability conditions of rock|interface systems were obtained. The analytic results show that before the damage zone reaches the edges of rock the systems can be stable or instable that depends on the comparison between the volume shear load in rock and interface friction force: if the former is more than the later the system is stable and otherwise instable; after the damage zone reaches the edges, the instability of systems depends on the loading and the materials properties of interface and there are significant effects of softening stiffness coefficient and the strength of interface on instability.