为了研究锚杆加固节理岩体的锚固机理,借助颗粒离散元软件PFC2D软件内嵌FISH语言分析了加载过程中锚杆和结构面之间的相互作用机理以及锚杆内部轴向和剪切应力情况,探讨了锚杆对结构面锚固效应和锚杆的变形破坏规律.结果表明:锚杆在剪切荷载作用下容易在结构面和锚杆交界位置发生“S”形变形并在节理面两侧形成塑性铰,导致锚杆在塑性铰处发生拉弯屈服,揭示了锚杆在剪切作用下的拉弯屈服机制,并从细观机制上阐明了锚杆对岩体结构面的支护作用主要体现为结构面内聚力的提高.
Focusing on the microscopic anchoring mechanism of bolt in jointed rock mass, a discrete element method- based research program was carried out to account for the microscopic interaction mechanism between the rock bolt and the joint during the loading process as well as the axial and the shear forces mobilized in the bolt. With the in- ner-embed FISH language in PFC, the deformation and stress characteristics of bolt in different deformation capacity were analyzed from the point of microcosmic. The results show that the shearing performance of rock joint anchored by bolt can be strengthened mainly because of the enhancement of cohesion; the bolt partly was deformed into “S” shape near the bolt-joint intersection. There exist two critical points in the loading process: one is in the bolt-joint intersection and the other at the plastic hinge point. The axial stress in bolt maximizes at the plastic hinge point, which will result in tension bending yielding phenomenon near the plastic hinge.