Seismic Response of Single Piles and Pile Groups

Abstract

A numerical study is presented on the kinematic response of groups of floating piles connected through rigid massless caps and subjected to vertically-propagating harmonic S waves. Pile-soil and pile-pile interaction effects are modeled rigorously. Parametric results for the effective seismic input motion at the pile cap, normalized by the free-field ground-surface motion, are displayed in dimensionless form for a number of typical pile-group configurations, in three idealized soil profiles. Pile-head fixity conditions and the pile/soil modulus ratio are found to affect the seismic response of both single piles and pile groups. The presented results can be utilized in assessing the influence of piles on the effective seismic excitation at the base of a structure.