隧道穿越软弱断层破碎带坍塌机理与变形控制措施研究

Study on Collapse Mechanism and Deformation Control Measures of Tunnel Crossing Weak Fault Fracture Zone

软弱断层破碎带岩体强度低,围岩自稳性差,地质条件复杂,隧道穿越软弱断层破碎带时易发生大变形、塌方等地质灾害。通过现场勘测,分析隧道穿越软弱断层破碎带坍塌机理,并提出注浆加固和设置临时钢支撑的围岩变形控制措施。现场监测结果表明,采用注浆加固和设置临时钢支撑的围岩变形控制措施后,隧道拱顶最大沉降为19.2mm,拱腰最大收敛为13.5mm,同时监测断面围岩应力和钢拱架应力基本稳定,可知变形控制措施可有效提高围岩稳定性。

The weak fault fracture zone has low rock strength,poor self⁃stability of surrounding rock and complex geological conditions.When the tunnel crosses weak fault fracture zone,geological disasters such as large deformation and collapse are prone to occur.Through field investigation,the collapse mechanism of the tunnel crossing weak fault fracture zone is analyzed,and the surrounding rock deformation control measures of grouting reinforcement and temporary steel support are put forward.The field monitoring results show that the maximum settlement of the tunnel vault is 19.2mm and the maximum convergence of the arch waist is 13.5mm after the surrounding rock deformation control measures of grouting reinforcement and temporary steel support are adopted.The surrounding rock stress and steel arch stress of the monitoring section are basically stable,and it can be seen that the deformation control measures can effectively improve the stability of the surrounding rock.