Numerical Simulation of Surrounding Rock Deformation and Grouting Reinforcement of Cross-Fault Tunnel under Different Excavation Methods.

Tunnel construction is susceptible to accidents such as loosening, deformation, collapse, and water inrush, especially under complex geological conditions like dense fault areas. These accidents can cause instability and damage to the tunnel. As a result, it is essential to conduct research on tunnel construction and grouting reinforcement technology in fault fracture zones to address these issues and ensure the safety of tunnel excavation projects. This study utilized the Xianglushan cross-fault tunnel to conduct a comprehensive analysis on the construction, support, and reinforcement of a tunnel crossing a fault fracture zone using the three-dimensional finite element numerical method. The study yielded the following research conclusions: The excavation conditions of the cross-fault tunnel array were analyzed to determine the optimal construction method for excavation while controlling deformation and stress in the surrounding rock. The middle partition method (CD method) was found to be the most suitable. Additionally, the effects of advanced reinforcement grouting on the cross-fault fracture zone tunnel were studied, and the optimal combination of grouting reinforcement range (140°) and grouting thickness (1m) was determined. The stress and deformation data obtained from on-site monitoring of the surrounding rock was slightly lower than the numerical simulation results. However, the change trend of both sets of data was found to be consistent. These research findings provide technical analysis and data support for the construction and design of cross-fault tunnels. [ABSTRACT FROM AUTHOR]