Dynamic Response Analysis Of Shallow-buried Cavities Under Anti-plane Line Source Load

It is a basic and important work in engineering seismic designs for determining the dynamic responses of tunnel structures and ground motions with the seismic load. When shallow buried cavities existing in underground, on one hand, the ground motion will be enlarge owning to the influence of the shallow buried cavity; on the other hand, the dynamic stress near the cavity will change because of the ground. Currently, the research for dynamic responses of deep-buried structures loaded by elastic waves is almost mature, the theories and methods have been used in mechanics and engineering, but for shallow-buried structures, the theoretical analysis, is not comprehensive. Especially when the dynamic responses are caused by line source load, the research is very rare. In this paper, we research the dynamic response of a shallow-buried cavity with arbitrary shape by anti-plane line source load. Which being a foundation for deep research of defect around the interface.In this paper, a scattering field of anti-plane line source load by shallow-buried cavities of arbitrary shape was investigated. A displacement field of complete elastic half-space via line source load was obtained by considering the symmetry of SH-wave. A scattered wave function, which satisfies the condition of stress free on the ground surface, is constructed. The methods of complex function and multi-polar coordinate system are used here. Then the problem comes to be solving a series of algebraic equations by considering the boundary conditions of arbitrary shape cavity. Numerical results of dynamic stress concentration and surface displacement are provided when the cavity is circular, ellipse or square. The influences of wave numbers or cavity shape upon the dynamic stress concentration factors around the cavity and the surface displacement are discussed.