Study on Geoacoustics Interface Wave Scattering Characteristic

Abstract

This paper introduces the propagation characterization of interface waves in elastic half space. In a layered medium, frequency dispersion exists and propagation models of interface waves can be researched using mode analysis. For a typical layered structure model, the propagation modes of interface waves can be calculated and the Green’s function can be obtained using propagation modes. In practical problems, there are buried objects in the medium. An interface wave scattering integral equation is derived, and scattering interface wave fields can be simulated by computer. For checking this arithmetic, the scattering displacement field can be calculated using the first mode of an interface wave. The convergence rapidity of the method has been proved to be very high by some practical examples, and the scattering strength can be obtained simultaneously. Sometimes, there are multiple objects buried in the medium, and the interface wave scattering integral equation can be spread into calculation of a multi‐objects scattering problem by the integral equation of the scattering elastic wave field associated with multi‐inhomogeneities. In this paper, the high mode scattering of an interface wave can be calculated also. In order to achieve the detection buried objects using interface wave, there is an experiment for verifying this method. In this experiment, the interface wave signal extraction, propagation velocity, propagation attenuation, and several other aspects are analyzed. The time difference between direct wave and echo wave in the received signal can be obtained according to the geometric relationship of buried objects, source and geophone array locations. The echo signal exists in the received signal.