Study On The Failure Mechanism Under Fault Movement And Seismic Dynamic Response Of The Chenglan Across-fault Tunnel

In recent years, with the rapid development of railway engineering, the tunnel project has become increasingly important. But in most areas of China, especially the western, the geological condition is complex, and the seismic phenomena emerges frequently. It is inevitable to be encountered with tunnels constructed across faults in the design of tunnels. How to ensure that the railway tunnel project in the normal function of earthquake have great practical significance. Therefore, the study of anti-breaking and anti-damping measures of railway tunnel across the fault is important. Based in Chengdu-lanzhou railway tunnel for the study, we use finite element software to do railway tunnel across the fault numerical simulation of anti-breaking and anti-damping.Firstly, the development overview and calculation theory of underground structure across the fault are summarized in this paper. Sum up all kinds of anti-breaking and anti-damping measures in the underground project. Summarize the principle of the calculation method which this discourse uses. Secdondly, the force characteristics under fault movement of tunnel across the fault are studied. The comparative analysis is performed based on the different rock parameter, the different dip angle and different width of fault. The internal forces, the displacement response of the tunnel lining as well as the plastic area of surrounding rock are supplied. Thirdly, the general rules of seismic response of tunnels across the fault are studied. Comparative analysis of different dip angle and width of fault on the dynamic response of the tunnel is performed. Summarize the acceleration, displacement and stress response of tunnels under different working conditions.Finally, according to the calculation results of numerical, and combining the situation the anti-breaking design is relatively shortage, some different anti-breaking measures are discussed. Comparative analysis of the advantages and disadvantages of different anti-breaking measures is performed. Then put forward a new optimized design.