Seismic Response of Strip Footings on Zoned Viscoelastic Soils

Abstract

Effects of the existence of a compliant bedrock and of the subsurface inhomogeneities on the site amplification and the seismic response of rigid strip footings are analyzed using boundary elements in a plane strain model for zoned viscoelastic media. Semielliptical soil deposits having several aspect ratios and boundless horizontal layers are assumed in the context of a parametric study. Several different values for the bedrock compliance and the foundation embedment are considered. The study is carried out for P and SV waves. The variation of the site amplification for the points along the surface of the different alluvial deposits is analyzed. The kinematic interaction of embedded foundations is shown to be very sensitive to the width of the alluvial deposit. It is also shown that, as a general rule, the site amplification and the seismic response of foundations decrease with bedrock flexibility. Results for the diffraction of waves by an elastic cylinder included in a complete space are also presented.