Scattering of an orthotropic semi-cylindrical alluvial valley by SH waves
CHEN Zhigang;Department of Mechanics and Civil Engineering,Jinan University;Key Laboratory of Disaster Forecast and Control in Engineering,Ministry of Education,Jinan University;
Solution to scattering of SH waves by a cylindrically orthotropic semi-cylindrical alluvial valley is given by using wave function expansion,and the effects of incident wave characteristics and orthotropy of alluvial valley on ground motion are investigated. The radial wave function in a cylindrically orthotropic alluvial valley satisfies the non-integer order Bessel equation under the incidence of steady-state SH waves. Numerical results show that the ground displacement amplitude of alluvial valley is closely related to incident waves frequency,incident waves direction,radial and circumferential shear modulus ratio of alluvial valley,and shear velocity and density ratio between half-space and alluvial valley. When alluvial valley is softer than half-space,the ground displacement amplitude of alluvial valley increases significantly. Meanwhile,the influence is more obvious on orthotropy of alluvial valley compared with isotropic one.