Vertical impedance of an end-bearing pile in viscoelastic soil

This paper presents a new method to derive the analytical solution for the vertical impedance of an end-bearing pile in viscoelastic soil. The soil is assumed as a homogeneous and isotropic layer, and the pile is considered as a one-dimensional Euler rod. Considering both the vertical and radial displacements of soil and soil-pile coupled vibration, the governing equations of the soil and pile are established. The volumetric strain of soil is obtained by transformation on the equations of soil and variable separation method. Then the vertical and radial displacements of soil are obtained accordingly. The displacement response and impedance function of pile are derived based on the continuity assumption of the displacement and stress between the pile and soil. The solution is verified by being compared with an existing solution obtained by introducing potential functions. Furthermore, a comparison with two other simplified solutions is conducted. Numerical examples are presented to analyze the vibration characteristics of the pile. Copyright (c) 2014 John Wiley & Sons, Ltd.