Study On Treatment Measures Of Slope Adverse Geological Body And Tunnel At The Entrance Of The Second Yaotou Tunnel

The deformed slope of the second Yaotou tunnel is located at the K45+045～+170 section of Yunnan Mengxin expressway. This tunnel is the control engineering of the expressway that has a direct impact on the entire project completion date, such as: the most complex geological condition, the most difficult construction, long construction period. The treatment for the deformed slope of the tunnel Entrance is directly related to operation safety and effectiveness and efficiency. The formation conditions, cause reason, deformation and failure mechanisms, the geometric characteristics of the boundary conditions are typical. Successful governance of the tunnel deformed slope has important practical and reference significance.Based on the deformation and failure deformation characteristics of the deformed slope of the second Yaotou tunnel, apply transmission coefficient method and block limit equilibrium method to analyze the slope stability in natural state and heavy rain state, discuss the potential unstability and the internal factors of damage. The results indicated: as the tunnel excavation and the emergence of a new overhead surface, the stability of the slope is declined, and the slope is un stability.After the stability anlysis of the slope, combination with special destruction mode, propose reasonable governance programs. As the special destruction mode in the early precursor, impose governance measures on vertical and horizontal direction. Impose pre-stressed anchor framework on the tunnel slope and impose common anti-slide pile on the right site tunnel.Finally, simulate the reinforcement effect by FLAC software, and comparewith the untreated slope. The simulation results indicate: the retaining measures (pre-stressed anchor framework, common anti-slide pile) satisfy the governance requestion, which can effectively enhance the stability of the slope.