Dynamic Analysis And Numerical Simulation Of Underground Interface Structure Under Earthquake Wave

The present thesis investigates the scattering problems and the dynamic stress concentration problems of SH-wave by ellipse cavities, U-shaped cavities and U-shaped lining in near field by the method of FEM. The FEM is a method of which transform the partial differential-coefficient equation's initial and boundary value issue to ordinary differential-coefficient equation's initial and boundary value problem (after space disperse) or a set of regular algebra equation. Then, use the direct integral calculus method of NEWMARK to solve solution, and get each node and element's displacement and stress solution vs. time. There are two problems in simulating SH-wave issue by finite element method. The first is establishing artificial boundary problem, because of simulating the infinite field from the finite field in which intercept from the infinite field, so we introduce artificial boundary. The second is solving all kinds of disadvantageous influence in space-time dispersing to reduce error. In additional, the problems of load's infliction and model's size should be considered. In this article, we found the finite element model in allusion to the problem above, solved the equation by the general finite element analysis software ANSYS, gave some node's displacement and stress solution vs. time and the dynamic stress concentration at the edge of cavity, discussed the result. Our analytic works in concrete are mainly as follows:Scattering of dynamic SH-wave and dynamic stress concentration problem are investigated by ellipse cavities in the whole space. The error and solution bringing from finite element disperse are expatiated. The finite element model and result are given. The influence on displacement of different finite element model's lateral boundary and the cavities' radius and the variety of dynamic stress concentration at different material of medium are discussed.Scattering of dynamic SH-wave and dynamic stress concentration problem are investigated by U-shaped cavities in half space. The result of finite element method and transmission and the result of displacement of the surface and the edge of cavity vs. time and the dynamic stress concentration factor of U-shaped cavity are given.