茶镇隧道施工位移监测与分析

Monitoring and Analysis of the Displacement of Chazhen Tunnel in Construction

茶镇隧道围岩软弱破碎稳定性差,变形大.为及时掌握施工过程中围岩及支护结构的变形特性,保证施工安全,对围岩及支护结构进行了拱顶下沉和周边收敛位移量测.通过对K225+266横断面量测数据的综合分析,揭示了该条隧道在Ⅴ类围岩以及特定支护情况下位移变化的规律,得到了围岩位移稳定约需2～3周的开挖时间以及4～5倍开挖洞径的距离.为合理确定隧道二次衬砌的施工时间提供了较为可靠的依据,同时通过对量测信息的及时反馈,指导了现场施工,确保了施工安全.

A field monitoring of crown settlement and lateral displacement convergence was conducted to ensure the safety of the construction of Chazhen tunnel for the weak surrounding rock.The characteristics of displacement of the tunnel with weak surrounding rock under certain supporting condition were exhibited based on the analysis of the monitoring data of the section K225＋266.It was shown that 2～3 weeks after the excavation and a distance of 4～5 times diameter of the tunnel at least between the excavation face and monitoring section were needed to ensure the stability of surrounding rock.These provide a reliable basis for the construction of the second liner and ensure the safety of the tunnel excavation.