隧道掘进机撑靴导致洞壁破坏机理的研究

摘要

Considering such three influence factors as the tunnel buried depth,tunnel diameter and surrounding rock strength,the interaction between T BM gripper and tunnel surrounding rocks,the surrounding rock deformation and failure laws were analyzed by using finite element analysis software ABAQUS,which were compared with the measured results. T he results show that the stability of surrounding rock increases with the tunnel buried depth increasing,the stability of surrounding rock gradually decreases and the changing amplitude is small with tunnel diameter increasing,the bearing capacity of tunnel surrounding rock decreases under the effect of gripper load with the shear strength decrease of the tunnel surrounding rock,which means that the internal friction angle of tunnel surrounding rock should not be less than 45 in practical engineering. Among the three influence factors,the tunnel surrounding rock stability is mostly sensitive to the change of surrounding rock strength,followed by the tunnel buried depth,and finally sensitive to the tunnel diameter. T he measured unilateral gripper support force is 24 900 ~25 900 kN in Northwest Liaoning water supply engineering and the unilateral gripper radial stress can be inferred as 5. 72 ~5. 95 M Pa,which is consistent with the simulation results.%考虑隧道埋深、隧道洞径和围岩强度3种影响因素，采用有限元软件 ABAQUS 建模，分析了全断面隧道掘进机撑靴与隧道围岩的相互作用、围岩变形和破坏的规律，并与实测结果进行了对比。结果表明：随隧道埋深的增加，隧道围岩的稳定性逐渐增强；随着隧道洞径的增大，隧道围岩的稳定性逐渐降低，但变化幅度较小；随着隧道围岩抗剪强度的降低，在撑靴荷载作用下隧道围岩的承载力逐渐降低，建议实际工程中隧道围岩的内摩擦角不能小于45°；3种影响因素中，隧道围岩的稳定性对于围岩强度的变化最为敏感，其次是隧道埋深，最后为隧道洞径；辽西北供水工程实测单侧撑靴支撑力为24900～25900 kN，可推断出单侧撑靴径向应力为5.72～5.95 MPa，与仿真计算结果一致。