多组非贯通裂隙岩石的压缩特性数值研究

Numerical Simulation of Rocks Containing Multiple Sets of Non-persistent Joints

裂隙岩体力学性质研究是非常复杂的课题,非贯通裂隙岩石的力学行为与裂隙的几何产状密切相关,裂纹的扩展贯通直接影响岩石的破坏。采用改进刚体弹簧方法,以随机均布Voronoi图为基础,生成不同裂隙产状的岩石数值模型,模拟含多组非贯通裂隙岩石的细观起裂和扩展过程。从细观和宏观两个方面分析了预制裂隙的贯通模式及其对岩石宏观破坏模式的影响;并得到沿平面破坏、阶梯状破坏、沿次生块体转动破坏三种破坏模式。通过分析岩石渐进破坏过程揭示其破坏机理;且定量分析了裂隙岩石在强度上表现出的各向异性特征。将数值计算结果与已有的岩石试验结果对比分析,表明数值与试验结果吻合较好。

The properties of jointed rock mass are very complicated. The mechanical behaviour of non-persistent jointed rock is closely related to the geometry of rock, and the initiation and propagation of the cracks has direct effect on the failure of the rock. To simulate the initiation and propagation of micro cracks, basing on random equis- paced Voronoi diagram, a modified rigid body spring method （RBSM） was used to generate different rock numerical models. The coalescence pattern of pre-existing flaws and failure mode of rock were analysed in both aspects of me- soscopic and macroscopic, test results showed three basic failure modes, i.e. failure through a planar surface, stepped failure and failure by rotation of new blocks. Meanwhile, analysis of rock progressive failure process reveals rock failure mechanism and the anisotropic characteristics of uniaxial compressive strength were discussed. Compar- ison with former experimental studies showed that both strength and deformation results analyzed by the numerical simulation are in good agreement with the experiment data.