Study On Seismic Dynamic Response And Damping Measures Of Mountain Tunnel Portal Tunnel

With the implementation of the western development strategy, a large number of roads, railways and hydroelectric tunnel project will be built in the vicinity of active faults and high-intensity earthquake zone;And because of the Wenchuan earthquake and 2010 World Conference on Earthquake-prone, causing people to work for more attention to earthquake damage.Therefore, as a tunnel and underground engineering research- ers ,working on the Mountain Tunnel Portal seismic dynamic response and damping measures are more of the times.First of all, the paper classify, organize and research about the tunnel seismic damage and seismic data about china and abroad and sum up Mountain Tunnel Portal types of geological disasters and the disaster-causing mechanism .Then the paper introduce the basic dynamic finite element method of the underground structures and the basic steps of dynamic finite element method to solve the problems.Secondly, the paper discusses the Tunnel Portal Dynamic Response Analysis of model building in the process of boundary conditions and key factors such as seismic wave input,And Sum up the tunnel portal section dynamic finite element analysis principles, the realization of artificial boundaries and seismic wave input method, at the same time the paper sum up and research the artificial boundaries and seismic wave input in finite element software ANSYS in the implementation.On this basis, this paper useing Chongqing Wushan to Fengjie peach Jiangya tunnel as an example, using ANSYS software to research the conditions of the incident seismic loads randomized study in different directions.based on the theory in the study,the paper discuss the internal forces and acceleration characteristics of the two aspects, and analyze the hole at the presence of the fault seismic response of tunnel lining structure, and the corresponding anti-damping measures.Finally, the paper use the BaoTeng high-speed Meng lian 1 as an engineering example, and use the three-dimensional finite element model to analyze the advantages and disadvantages of joint seismic fault zone settings, and by analyzing the set of different seismic gap distance on anti-damping properties of the tunnel.Innovation of this paper is: through calculating of the three-dimensional finite element model, one is found in horizontal incident earthquake wave vertical incidence ratio greater impact on the tunnel structure; second is the fault of tunnel lining in the waist of the most easily damaged arch foot; The third is to find the distance between different seismic gap on the Tunnel Seismic was obvious. The three conclusions are in good agreement with the actual project example, the conclusion can be used for the design and construction of reference of mountain tunnel entrance.