玄武岩隧道两台阶法施工过程中支护受力及变形监测分析

本文工程背景为丽香铁路中义隧道。该隧道位置地质构造复杂，新构造运动剧烈，岩体整体性差，且高跨比较大（约1.4），边墙结构设计为直墙，对水平收敛控制有不利影响，造成开挖后围岩有较明显变形。采用现场监测与理论分析相协同的方法，对玄武岩隧道两台阶法施工过程中结构受力及隧道拱顶下沉和水平净空收敛变形进行监测，获取监控数据以反映现场初支变形情况，为支护参数调整、二衬施作时机等提供参考。

Monitoring and analysis of support force and deformation during the construction of basalt tunnel with two-step method

This paper is based on Zhongyi Tunnel project of Lixiang Railway. The geological structure of the tunnel location is complex, the neotectonic movement is intense, the integrity of rock mass is poor, and the height-span ratio is relatively large, about 1.4. The structure of the side wall is designed as a straight wall, which has a negative impact on the horizontal convergence control, resulting in obvious deformation of the surrounding rock after excavation. Combining the field monitoring and theoretical analysis, this paper monitors the structural stress during the construction of basalt tunnel with two-step method and the deformation of tunnel vault settlement and horizontal clearance convergence. The monitoring data are obtained to reflect the deformation of initial support on-site, and provide reference for the adjustment of support parameters and the timing of secondary lining construction.