锚固的贯通节理岩体剪切破坏特性分析

为了研究节理对锚固岩体力学特征和失稳损伤演化的影响,采用对锚固贯通节理岩体进行室内剪切试验和PFC^2D数值模拟的方法,研究不同节理倾角下锚固贯通节理岩体剪切性能的作用机制和破坏模式,研究结果表明:(1)随着节理倾角变化,贯通节理岩体呈现出不同的破坏形式,锚固贯通节理岩体的抗剪强度与剪切位移曲线并不是呈线性增长,而是呈"双驼峰"趋势。(2)锚固体系在剪切试验的过程中,节理面颗粒的接触方位角会发生一定程度的改变,主要集中在锚杆和节理倾角附近。(3)锚固体系在剪切试验的过程中,会因为颗粒间黏结键的断裂生成裂纹,裂纹数生成的越少,其抗剪强度越高,裂纹分为张拉裂纹和剪切裂纹,并且张拉裂纹的数量要远远大于剪切裂纹的数量。研究结论可用于实际工程破坏模式的预测和岩体工程稳定性评价。

Shear failure mode of anchored rock mass with through joints

In order to study the influence of joints to the mechanical characteristics of rock mass and the evolution of instability damage, by using anchoring through joint rock PFC2D doing indoor shear test and numerical simulation method, studying the anchoring through joint rock mass under different joint angle shear performance of the mechanism of behaviour and failure mode, the result shows that:(1)with joint angle changing, it presents different failure modes through joint rock samples, and anchor through joint shear strength of rock mass and the shear displacement curve is not a linear growth, but a trend of "double hump".(2)During the shear test of the anchorage system, the contact azimuth angle of jointed surface particles changes in a certain extent, mainly in the vicinity of the anchor rod and the joint inclination angle.(3)During the shear test the anchorage system, it will generate cracks in the anchorage system due to the fracture of the interparticle bonding bond. The fewer the number of cracks are, the higher the shear strength is. The cracks include tensile crack and shear crack, and the number of tensile crack is much larger than the shear crack's.The results can be used to predict the actual failure mode and evaluate the stability of rock mass engineering.