Study On The Stability Of Surrounding Rock And Slope In Exit Shallow Buried Section Of Mazui Tunnel

With the rapid development of economy and the progress of science and technology, The government is bound to provide more security,Comfortable, fast and convenient transportation. The construction of the highway has become a necessity. The highway construction has been promoted from plain to mountainous area With the implementation of the western development strategy, Corresponding to it, Highway tunnels have been developed rapidly. Tunnel engineering is often the control project in the construction of the highway. The period and quality of tunnel construction will directly affect the completion of the whole highway. In areas of mountains and hills, The tunnel is inevitable to cross the areas of complex geological conditions. the entrance and exit section of Tunnel in mountain area Generally encountered shallow buried section of weak and broken rock,And accompanied Easy slide Slope. The complexity of the mechanical properties often Influence the normal construction.This paper mainly studies the shallow buried section of the mazui tunnel. The surrounding rock in the tunnel area is mainly silty clay and weathered shale. The weak and fractured rock has brought difficulty for construction of the tunnel. This paper carried out Research work of the deformation mechanism of the slope and tunnel entrance. The results are helpful to establish the deformation and stability theory of the tunnel entrance section, At the same time can provide theoretical guidance for the development of effective engineering measures.The main contents and conclusions of this paper are as follow:①Based on Tunnel engineering geological condition, This paper use Transfer coefficient method for limit equilibrium theory to calculate the stability coefficient of landslide, After calculation, We know the stability coefficient of the slope is less than the specified safety value, So the slope is Need to carry out supporting measures to ensure the safety of tunnel construction.②By introducing stress function, the displacement and stress formula of the surrounding of the tunnel are discussed by considering the complex displacement boundary conditions of the tunnel periphery under the influence of radial shrinkage, elliptical deformation and vertical displacement.③Based on the analysis of the deformation and the sliding force of the tunnel, the anchorage section of the anti slide pile is calculated, and the shear force and bending moment of the load section are verified. In addition, This paper introduce the mechanism of pipe roof support and design parameters, advanced small pipe grouting and other auxiliary construction measures in detail.④With the aid of numerical analysis of the export section, This paper simulate the tunnel excavation of CD method, Through simulation analysis,We know CD method can greatly improved the stress state, the initial support will effectively control the surrounding deformation of the tunnel. In addition, Shear stress usually concentrate in front of the side slope, so we should pay attention to slope protection.⑤Field monitoring observed the settlement of the slope surface, Vault settlement and surrounding convergence. After processing the observed data, we get the Deformation law of vault settlement with the distribution of excavation, And the relationship between the surface subsidence and the spatial position of the tunnel.