Diffraction around Circular Canyon in Elastic Wedge Space by Plane SH-Waves

Abstract

The wave propagation behavior in an elastic wedge-shaped medium, with a circular canyon at its vertex, has been studied. In particular, an analytic closed-form solution has been derived and solved for the case of plane shear horizontal- (SH) or source-emitted SH-wave incidence. The analysis demonstrates that the resulting surface displacement profile depends, as expected and as in similar analyses, on numerous parameters including the angle of the wedge, the frequency of the incident wave, the material properties of the media, and the angle of incidence. The results, especially in the context of varying wedge angles, provided intriguing results that help to explain geophysical observations regarding the amplification of seismic energy as a function of site conditions. The amplification resulting from a canyon in a sloping wedge space is now greater than two, exceeding that from the same canyon in a flat wedge space. The closed-form analytic solution also provides a set of results that can be used for comparison with those from approximation or other numerical methods.