Seismic p-y Model of Pile Foundation Taking into Account Soil-Nonlinearity

It is well known that the earthquake response of a pile-supported structure is strongly affected by dynamic soil-pile interaction. When the structure is subjected to severe ground motion, the soil behaves in a nonlinear manner. Two kinds of soil nonlinearity will affect the characteristics of dynamic soil-pile interaction. One is the nonlinearity which appears in the soil surrounding the pile and the other is the nonlinearity which appears in the free-field. The nonlinearity of soil surrounding the pile is caused by the inertia force transmitted from the superstructure onto the pile head (i.e., local-nonlinearity). Soil nonlinearity in the free-field is caused by the transmission of shear waves (i.e., site-nonlinearity). Various tools based on the Sway-Rocking model have been developed to analyze nonlinear dynamic soil-pile interaction. Most of these methods, however, only take into account local-nonlinearity effects. Therefore, a methodology to evaluate the effects of both local-nonlinearity and site-nonlinearity are developed in the paper. The accuracy of this method is confirmed by comparing simulated and experiment results.