Nonlinear Axial Interaction in Pile Dynamics

A model for the analysis of pile axial response to transient dynamic loading and to harmonic loading is presented, allowing for nonlinear behavior of the soil adjacent to the pile, energy dissipation through different types of damping, and the loading rate dependency of the soil resistance. The approach is used to establish equivalent linear stiffness and damping parameters of single piles as well as dynamic interaction factors for approximate nonlinear analysis of pile groups. The applicability of these parameters to the pile‐group analysis was examined, and a reasonable agreement with the direct analysis was found. The superposition technique may be used to analyze the response of small pile groups. Also, the dynamic stiffness of pile groups is greatly affected by both the nonlinear behavior of the soil and the slippage between the pile and soil. For a basic range of soil and pile parameters, equivalent linear stiffness and damping parameters of single piles and interaction factors for approximate nonlinear analysis are provided.