The Scattering Of SH-Wave By Subsurface Circular Cavity And Inclusions With A Layer

The scattering of SH-wave by subsurface circular cavity and circular inclusions in a layered elastic half-space was researched on the category of elasticity. The solution of the dynamic stress concentration of SH-wave by a subsurface circular cavity and circular inclusions in a layered elastic half-space was solved based on the complex function method, wave functions expansion method and moving coordinate. The main contents are as follow:(1) The principle of orthodrome assumption was used. The principle assumes that the horizontal surface in infinite half-space is replaced by circular arc with large radius. Under this assumption, wave function can be expanded on the horizontal surface in infinite half-space. On the basis of wave function expansion, scattering waves on the surface of half-space can be substituted by cohesion waves.(2) On complex plane, general solution of the wave function which expresses the scattering of circular structure underground under SH-wave was given using the theory of Helmholtz, and then the solution of controlling equation was finished by boundary conditions. The solution of controlling equation was converted into infinite linear algebraic equations by expansion of complex Fourier-Hankel series. Unknown coefficient in wave function was obtained after the finite terms in equations were truncated, and the solution of this problem was completed.(3) The ground motion and the dynamic stress concentration factors around the circular inclusion and circular cavity were discussed according to two numerical examples. The variation law of dynamic stress concentration coefficient and surface displacement was also analyzed under different factors. The results show that the parameters of surface overburden layer in half-space have great influence on the scattering of SH-wave, which can change the distribution of dynamic stress concentration coefficient and surface displacement around the circular inclusion and circular cavity. The frequency and angle of incident wave and the distance between circular inclusion and cavity badly affect the dynamic stress concentration coefficient. The wave number, buried depth of the structure underground and the parameters of surface overburden layer all can change the surface displacement obviously.