ABSTRACT
This paper summarizes a new continuum model for the nonlinear soil-pile-structure interaction under earthquake excitations. The earthquake excitation is modeled as a harmonic shear wave, and the soil is considered to compose of an inner nonlinear zone around the pile and an outer linear elastic zone. The pile-soil-pile interaction is considered by using a Winkler model with its spring constant estimated from the wave-interference. The difference of shaking for the coupled system and the free field may be up to three times when l is at the first natural frequency of the structure or at high frequency. There exists a critical ground shaking at which the seismic response is the largest. The response of pin-piled structures can either larger or smaller than that of fixed-piled structures. In general, the interactions are highly dependent of the excitation frequency, the pile-to-pile distance, the amplitude of ground excitation, and the nonlinearity of soil.
