عنوان مقاله [English]
During earthquakes, piles undergo stresses due both motion of the superstructure (i.e. inertial interaction) and that of the surrounding soil (i.e. kinematic interaction). In practice, structural engineers commonly take into account stresses induced by the inertial interaction, which is responsible for pile head failure, but they neglect the effects of the kinematic interaction that is responsible for failures along pile’s length in the case of layered soils with highly contrasting mechanical characteristics even in the absence of the superstructure. Thus, the evaluation of kinematic forces developing in piles during earthquakes has been receiving increased interest from the researchers. Numerical methods for the analysis of kinematic soil-pile interaction can be classified into two groups; continuum-based approaches and Winkler methods [1-3]. It has been customary in professional engineering and research practices to assume a linear behaviour for the soil and the pile foundation. However, under strong excitation, the nonlinear behaviour of soil media at the soil-pile interface has a strong influence on the response of the pile foundation. The aim of this study is to investigate the influence of soil nonlinearities on the kinematic interaction forces of pile groups embedded in layered soil deposits during seismic actions. Figure (1) shows the assumed soil-pile group case with 5 by 5 piles embedded in two layer subsoil profile. The pile has been considered as an elastic beam, while the soils have been modelled using the elastic-plastic solid element. The corresponding 3D finite element mesh has been shown in Figure (2). Based on the symmetry, only half of the model is meshed.