Abstract:Most of the studies on the dynamic response of pile assumed that the soil surrounding the pile are homogenous in radial direction in the past decades,and fewer researchers took the inhomogeneity into account. Moreover,the inhomogeneous model of soil used in these studies may not be suitable for the fact according to some special researches. A new model for the analysis of pile axial response to harmonic loading is presented. Firstly,the soil is assumed to be viscoelastic and radially inhomogeneous. The surrounding soil is divided into two regions:the outer region is homogenous and extend far infinitely,the inner region is divided multizone of which parameters can be considered linearly or nonlinearly. By utilizing the plane strain model and combining the boundary condition,complex stiffness at the interface of pile and soil is derived by complex stiffness transfer method from outer zone to inner zone. Then,the pile is modeled one-dimensional elastic theory valid for long straight bar. Through mathematical derivations,the expression of the impedance function and frequency response function at pile top are derived. Subsequently,the relevant responses in time domain are obtained by the convolution theorem and the inverse Fourier transform. Finally,the selected numerical results are obtained to investigate the influences of the changes of the soil parameters caused by construction on the dynamic responses of pile in frequency and time domain;and it is proven that the new soil model is reasonable. Moreover,the soil model considering the soil inhomogeneity is fitting for the engineering practice and can provide new theoretical support for the aseismic design and pile integrality testing.