Comparative Study On Seismic Dynamic Response For Expressway Multi-Arch Tunnel And Neighborhood Tunnel

By the factors of the special terrain and geological conditions, the general lines, the lines between Bridges and Tunnels, project cost and manner restrictions and so on, double-line spacing around the tunnel can not guarantee to meet regulatory requirements. The program of arch tunnels and neighborhood tunnels has become an important options in order to obtain good technical economic and environmental benefits. Study on earthquake dynamic response of the multi-arch tunnels and neighborhood tunnels on high-intensity earthquake zones has an important value and social significance.In this paper, the numerical analysis of the dynamic time history in the process of dynamic analysis, artificial boundary conditions, damping model to calculate the region, and discrete method were discussed. In the meantime, such a random seismic signal that exist in the baseline drift, to be cost-effective use of least squares Law had their baseline correction. Then by the use of FLAC^3D , an finite difference software, the dynamic response analysis of the multi-arch tunnel and the neighborhood tunnel are compared and analyzed, and the main contents are as follows:1) comparative analysis of two types of conventional structure of the tunnel with different sections and the conditions of figure-power in response to the earthquake are performed. The effects of different parameters of surrounding rock, the depth of the different structure of the tunnel where the two types of dynamic response of the law, a comparative analysis of corresponding changes in the parameters of the tunnel structure of the two types of seismic dynamic response are analyzed. And seismic excitation intensity and direction of both the structure of the tunnel for two types are comparatively studied.2) comparative analysis of the middle wall between the multi-arch tunnels and neighborhood tunnels in response to the earthquake are performed. Respectively on the opening hole with the figure above two types of structures in the tunnel wall and the rock wall in the principal stress comparative analysis, come in with the wall rock wall tensile stress and minimum principal stress concentrated positions.3) the seismic analysis of the portal section of the Xudianzi tunnel are performed with numerical simulation, the dynamic response characteristics of the structures from double-arch tunnel to the neighborhood tunnele are studied. The most disadvantaged positions are found .