Reduction of peak ground velocity by nonlinear soil response - I: Excitation by SH pulse

We study the reduction of peak velocity on the ground surface of a soil valley for excitation by an SH half-sine pulse. This reduction is caused by the loss of wave energy during propagation accompanied by large nonlinear strains and strain localizations in the soil medium. Our aim is to find a physically plausible explanation for observed spatial variations of damaged buildings, which suggests that damage is significantly larger in areas where the soil experiences little or no nonlinear deformations. In order to create simple and manageable calculations, we work with the most elementary representation of the soil valley (finite soil box) and assume the soil to behave like an elasto-plastic material. Our work belongs in the category of Gedanken numerical experiments