Interaction Model for Torsional Dynamic Response of Thin-Wall Pipe Piles Embedded in Both Vertically and Radially Inhomogeneous Soil

Abstract

The inhomogeneity of soil is a ubiquitous problem for pile foundations due to, for example, pile installation (radial inhomogeneity) or the natural sedimentation of soil (vertical inhomogeneity). Most continuum theory solves soil equations by artificially setting the displacement at the inner soil core as zero, which results in the misestimation of soil shear strength. Although the additional mass model avoids the utilization of artificial boundaries, the internal deformation of soil is overlooked. In this paper, the modified additional mass model is proposed. The capacity of this model is verified through comparison with former studies. Through a comprehensive parametric study, it was found that (1) the inhomogeneity of soil has significant influence on pile stiffness and damping amplitudes, (2) the length and strength of the pile would affect the resonance frequency of the soil–pile system, (3) only the soil within the range of 0.3r1 to the pile shaft has a visible effect on the dynamic response at the pile head.