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针对中空注浆锚索出现的受力问题,利用FLAC~(3D)内置的cable结构单元对中空注浆锚索进行模拟拉拔实验,分析中空注浆锚索在全长锚固时锚索在不同拉拔载荷下围岩和锚索的应力位移演化规律以及锚索轴力演化特征。模拟结果表明:在相同拉拔载荷下,中空注浆锚索周围0~0.5 m范围内的围岩,越靠近中空注浆锚索的围岩位移变化量越大;在不同载荷同一位置围岩的位移随着拉力的增加而逐渐增大,围岩位移沿着索体径向方向上总体呈负指数下降,随着拉力逐渐增加,在锚索与锚固剂的连接面处岩体应力由拉应力逐渐变为压应力。当拉拔载荷在400~440 kN时,锚索位移量突然增加,锚索逐渐发生破坏,破坏之前,最大位移量达到250 mm左右,瞬间被拉断后,锚索位移量达到400 mm左右。在不同拉拔载荷下,锚索受力由锚索底部逐渐传递到锚固段,剪切滑移破坏逐渐上升,最终导致锚索发生破断。通过模拟和现场实践表明应用中空注浆锚索支护巷道具有一定实用性。
Aiming at the problem of the force of the hollow grouting anchor cable, the hollow drawing grouting anchor cable was simulated by using the cable structure unit built in FLAC ~ (3D) Evolution of Stress Displacement of Surrounding Rock and Anchor Cable under Tension Load and Evolution Characteristics of Axial Force of Anchor Cable. The simulation results show that the more the surrounding rock in the range of 0-0.5 m around the hollow grouting anchor cable is, the greater the variation of the surrounding rock displacement is. In the same load of the same location, With the increase of tensile force, the displacement of surrounding rock decreases negatively exponentially along the radial direction of the cable body. With the increase of the tensile force, the stress of the rock mass at the connection surface between the anchor cable and the anchor agent increases The stress gradually becomes compressive stress. When the drawing load is 400-440 kN, the displacement of the cable suddenly increases and the cable breaks down gradually. Before the failure, the maximum displacement reaches about 250 mm. After being momentarily broken, the displacement of the cable is about 400 mm. Under different drawing loads, the force of the anchor cable is gradually transferred from the bottom of the anchor to the anchorage section, and the shear slip damage gradually increases, finally resulting in the breaking of the anchor cable. Through the simulation and on-site practice shows that the application of hollow grouting anchor cableway has some practicality.