Mechanism Analysis and Research on Engineering Countermeasures of Unsymmetrically Pressed Mountain Tunnel Based on Finite Element Method

Combined with the numerical simulation of finite element method, this article explores the mechanism and distribution of unsymmetrically pressed mountain tunnel. According to the destruction patterns of surrounding rock, different calculation methods are used to calculate the safety of lining structure, and corresponding countermeasures against the main factors influencing the stability of surrounding rock are introduced. Analytical results indicated that external lining load is formed mainly of the weight of upper rocks and the shear displacement caused load in rupture zone. Rupture zone has great influence on rock slope stability. Due to the existence of the fault rupture zone, the mechanical condition at the intersection of lining structure and rupture zone is obviously unfavorable, which causes sudden changes. According to the poor mechanical properties of fault rupture zone and the phenomenon of unsymmetrical pressure, we bring out several countermeasures. The reinforcement program of combining anti-slide pile with molten steel pipe is used to improve the stability of structure. Meanwhile, retaining wall and other countermeasures are used to improve the load condition of the tunnel. The height and position of retaining wall are associated with the deflection angle and the fault strike, which should be determined by specific calculations.