Research On Construction Of Dingxi Tunnel

In recent years, China’s railway construction is very fast,, in railway construction,encounter more complex stratum. This paper is based on the Dingxi tunnel,and study the tunnel construction method through the stratum of complex construction for the purpose.Dingxi tunnel goes through gas coal strata, karst caves, fractured zones, etc.Tunnel construction is dangerousand difficulty. To take reasonable and efficient construction methods, the paper choses the commonly used three-step excavation method and CD method to compare and analysis rock stress field, displacement field,the plastic deformation zone and supporting structure. And combining the characteristics of both the tunnel construction method to determine construction methods.With the help of Ansys finite element software to analyze the three-dimensional numerical simulations, it can effectively analyze the impact on the surrounding rock and supporting structure between different excavation step,which closer to the actual construction from the spatial effects and time effects.In the construction of complex formation, regulating safe and effective method is important for construction. According to the characteristics of the tunnel information construction, establish the monitoring and measurement system during tunnel construction process to verify the security and stability of the supporting structure by monitoring data, for selecting the monitoring data of several typical section of this article as the representative for analysis supporting structure deformation displacement trend. Another tunnel construction encountered karst area, gas Stratum and fracture zone, for successful through the complex strata, developed a more detailed construction technology programs and measures.