Grouting Material Development and Treatment of Water and Mud Inflow Caused by TBM Tunneling in Fault Zones

Abstract

Water and mud inflow caused by TBM (Tunnel Boring Machine) tunneling in fault zones is a serious and troublesome geological obstacle in underground engineering. The common solving method is to disassemble the cutterhead and tunnel shield of TBM, which can result in the unstability of the surrounding rock in the process of disassembly. Grouting without disassembly is a practicable method to reinforce the surrounding rock and reduce water inflow. However, the common grouting materials are difficult to remain under the influence of fracture flow, and the grouting pressure makes the broken surrounding rock and tunnel shield much easier to consolidate together. In order to solve the above problems, a new type of grouting material GT-1 was developed. The GT-1 grouting material possesses the characteristics of high and early strength. The initial setting time of grouting slurry is 92–452 s, and the retention rate of slurry in the water flow velocity (0.4 m/s) is 95%. According to the analysis of GT-1 grouting material and the position of water and mud inflow, the arrangement of grouting holes, grouting parameters and safety control in the process of grouting are designed, the grouting parameters are adjusted based on the real-time deformation of surrounding rock. The grouting effect comprehensive evaluation system which includes physical exploration method, core-drilling method and excavation method is built to examine the grouting effect. The TBM excavated across fault zones smoothly, which possesses directing significance for similar projects.