The 3D Seismic Response Analysis Of Metro Turnel Based On Multi-yield Surface Dynamic Constitutive Model

In recent years, underground structures have been utilized widely in energy sources, traffic, city construction, and national defending engineering, etc.With the development of agricultural industry and the acceleration of modernization, it becomes more important to built structures like metro tunnels. At present, space underground has been explored as an resource. As most areas of our country belong to earthquake-fortified regions, anti-seism and security evaluation of metro tunnels has important academic theoretical and practical value. Project planners are paying much more attention to it.This paper analyzed the seismic response of 3D metro tunnels. Since single yield surface constitutive models are not suitable for soil dynamic analysis and calculation and recent universal finite element software do adopt that kinds of constitutive models(such as DP model), a dynamic nonlinear finite element program is designed on the base of multi-yield surface elastoplastic constitutive models of saturated sands that Xu Gan-cheng presents. This programe can utilize universal finite element program to do preprocessor and postprocessor via data permutation.This paper utilized finite element programe and universal finite element program to analyse the dynamic seismic response of a 3D tunnel with double holes, and then contrasted the results based on the two different models, show the advantages of multi-yield surface elastoplastic constitutive model in dynamic analysis. With the motivation of pointing out the disadvantages of 2D model in analysis, also give out the danymic characteristic of the 3D model of the turnel along its axial direction,and present reference and argument for design and evaluation of practical project.