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为研究锚杆锚固对节理岩体剪切性能的影响规律及锚杆抗剪作用机制,开展不同锚杆倾角及不同法向应力作用下加锚节理岩体室内剪切试验研究,探究加锚节理岩体在法向力及剪切力作用下的变形和受力特征,对比分析节理岩体锚固前与锚固后的剪切变形规律,讨论锚杆倾角、节理面法向应力等因素对节理岩体抗剪性能的影响。试验结果表明,锚杆锚固能够有效地增加节理面的黏聚力和内摩擦角,提高节理岩体的抗剪强度;锚杆倾角对加锚节理岩体的抗剪强度及剪切变形规律有重大影响,较大的锚杆倾角有利于发挥锚杆的“销钉”抗剪作用;节理岩体施加锚杆后其剪力–位移曲线存在弹性阶段、屈服阶段及塑性变形阶段3个区段;在锚杆倾角相同的条件下加锚节理岩体的抗剪强度随节理面法向应力的增加而增大。分析试验后试件破坏形态可知,加锚节理岩体中锚杆的屈服破坏主要发生在节理面附近的区段,岩体材料由于锚杆横向的挤压作用,也会在节理面附近发生局部破坏现象。
In order to study the influence law of bolt anchorage on the shear performance of jointed rock mass and the mechanism of shear resistance of anchor rock, indoor shear tests of anchored jointed rock mass under different anchor angles and different normal stresses are carried out to investigate the effect of anchor joint reinforcement The deformation and stress characteristics of rock mass under normal force and shear stress are compared and analyzed. The shear deformation rules of the rock mass before and after anchorage are comparatively analyzed. Factors such as the inclination angle of the anchor rod and the normal stress of the joint surface are discussed. Body shear resistance. The experimental results show that the anchorage of anchor can effectively increase the cohesion and internal friction angle of the joint surface and improve the shear strength of the jointed rock mass. The shear strength and shear deformation of anchored rock mass with anchor dip In the jointed rock mass, the shear-displacement curve of the jointed rock mass has the elastic stage, the yield stage and the plastic deformation stage The shear strength of rock mass reinforced by jointed joints increases with the increase of normal stress of jointed joints under the condition of the same inclination angle of rock bolts. After analyzing the failure morphology of the specimens after the test, it is known that the yield failure of the anchor rod in the anchored jointed rock mass mainly occurs in the section near the joint surface. Due to the lateral extrusion of the rock bolt, the rock material also locally occurs near the joint surface Destroy the phenomenon.