COMPREHENSIVE DEFORMATION CONTROL TECHNOLOGY FOR SHALLOW BURIED TUNNEL IN AEOLIAN SANDY LOESS

This paper aims to reduce the ground surface settlement and control the construction risk of excavating shallow buried tunnel in aeolian sandy loess. It adopts the self-drilling pipe roof pre-reinforcement technology to control the surrounding rock deformation. The mechanical effect and deformation features is predicted by numerical simulation method before the excavation. Then, the mechanical parameters of the intrusion section were obtained by inversion calculation method using deformation monitoring data, which provides the reference for whole-process numerical simulation and comprehensive deformation control. The simulation finds that the maximum ground settlement at the intrusion section is 11.4 mm, the maximum vault sinking is 30.4 mm, and the maximum horizontal convergence is 48.5 mm. The self-drilling pipe roof pre-reinforcement technology can provide continuous longitudinal support, withstand the pressure of invading rock, and control surface settlement. The radial self-drilling anchor and pipe roof, along with the annular steel arch and feet-lock anchor, constitute the active and passive protection system for controlling rock deformation, which is proven to be an effective system to solve the problem of pre-reinforcement for the weak surrounding rock of the tunnel.