A computational model of soil-pile interaction behavior in pile and pile group was developed in this paper. Particular attention was paid to making the model simple and capable of taking into account nonlinear soil behavior, such as gapping and slippage between soil and pile, and cyclic behavior of soil. The model was developed within the frame work of the Winkler model defined in plane strain conditions. In order to analyze transient dynamic response in a rigorous manner, the model was formulated in the time domain using a step-by-step method. A transfer matrix approach was also adopted in the response computation. The proposed nonlinear model was verified with rigorous solutions and the nonlinear behavior with gapping and slippage were discussed based on the computational results
