Coupled horizontal and rocking vibration, and seismic shear-wave scattering of a piled plate on a transversely isotropic half-space

Abstract

A boundary element model of a piled raft foundation under horizontal and rocking excitations is presented. Excitations are time-harmonic and can be either horizontal loads and rocking moments applied to the raft, or a vertically-propagating seismic shear wave. The raft is modeled as a rigid circular plate bonded to the surface of the soil, and the pile is an elastic body embedded in the soil. The soil is a three-dimensional, transversely isotropic half-space. Contact tractions at the plate–soil and pile–soil interfaces are obtained by a numerical integration of Green’s functions for the aforementioned half-space at discrete points. The equation of motion for the discretized piled raft is obtained upon establishing equilibrium and continuity conditions between foundation and soil throughout those interfaces. The paper investigates the effect of foundation and soil parameters in the response of the system to both external and seismic excitations.