乌鞘岭隧道F7断层区段左线迂回导坑监控量测

兰新复线兰武段乌鞘岭隧道F7断层,为区域性大断层,地应力高。施工过程中,围岩变形达1 m以上,初期支护出现多处变形侵限及坍塌事故。为保证隧道的正常施工,掌握围岩动态和支护结构的工作状态,及时优化、更改预设计,在左线迂回导坑做试验段,进行了拱顶下沉、水平收敛、锚杆轴力、初支混凝土应力、初支围岩压力、初支钢架应力等多项涉及围岩稳定性及支护合理性参数的跟踪量测,利用量测结果指导正洞设计施工及预见事故和险情,以便及时采取措施,保证了隧道顺利贯通。

The Monitoring and Application of Left Line bypass in F7 Fault of Wushaoling Tunnel

F7 fault of Wushaoling tunnel, which lies in Lanzhou-Wuwei section of Lanxin railway line, is a large regional fault with high geostress. During the tunnel construction, the surrounding rock deformation reached more than 1 m, and limit contour deformation and collapse had happened in many places. In order to ensure the construction safety, measures were brought into effect in left line bypass to help to hold the working conditions of the surrounding rock and support. The monitoring data, which consists of many measurements relating to the surrounding rock stability and the support rationality, such as the settlement of arch crown, the horizontal convergency, the axial force of rock bolt, the surrounding rock pressure, the steel liner plate stress, the shotctete stress, were fed back to the construction to guide the design and construction and to forecast danger of the main line so that measures could be taken in time to guarantee the construction safety.