断续节理扩展机制的离散元分析

采用离散元数值法研究断续节理扩展贯通机制对工程岩体的稳定性具有重要意义，为此引入应力强度因子，基于裂纹Ⅱ型断裂判据，提出了考虑岩桥渐进破坏特征的粘聚力弱化函数，将粘聚力弱化函数用FISH编程语言内嵌至UDEC中，并在变形块体内预设潜在节理面表征岩桥的破坏路径，按Mohr-Coulomb屈服准则进行节理扩展分析，实现了断续节理在不同压应力状态下的直剪试验模拟，且真实反映了断续节理中节理面开裂、贯通、扩展的全动态过程，数值仿真结果与已有的试验结果吻合较好，从而验证了该方法的正确有效性。

Discrete Element Analysis of Progressive Failure Mechanisms of Discontinuous Joints

It is of great significance to study the progressive failure mechanisms of rock masses which contain pre-existing discontinuous by introducing the discrete element method for analyzing the stability of the engineering rock mass. Considering characteristics of progressive failure of rock bridge, an attenuation law of virtual joint cohesion parameters is proposed through introducing the stress intensity factor. In order to simulate the initiation and propagation processes of discontinuous joints in direct shear tests under different normal stresses, the law programmed in Fish language, is plugged into UDEC. Virtual joints are preset in deformable rock masses, providing potential paths for block failure and fracture propagation. Coinciding well with experimental results, numerical results of the Mohr-Coulomb (MC) joint constitutive models show that the proposed method can simulate the failure process of rock mass accurately and effectively, which reflects the dynamic progress of initiation, extending and connecting of joints inside rock mass.