Dynamic response analysis of pile-soil interaction during pile driving by torsional vibration

Abstract

This paper presents a precise theoretical model for pile-soil interaction during torsional vibration piling, offering an effective method for analyzing the response characteristics of pile-soil coupling throughout the pile driving process. In this analysis, the torsional dynamic response of a pipe pile in a linear elastic soil subjected to harmonic torsional load is investigated. Firstly, a vibration hammer-pile-soil torsional vibration piling system is developed to investigate the torsional vibration behavior under friction-coupled conditions by considering the fixed connection between the vibration hammer and the top of the pile, as well as the coupling characteristics between the bottom of the pile and the soil. Based on the separation of variables method and a 1D elastic theory, the torsional vibration differential equations of the pile are established and solved to research the torsional response and shear stress of the pile by considering frictional resistance between the pile and the soil. Secondly, a parametric study is conducted to examine the influence of soil parameters on the vibration responses. The soil is modeled as a linear elastic medium, and the response of soil is analyzed under the torsional vibration. The Integral Transform Method is employed to convert the soil vector wave equation from the space-time domain to the frequency-wavenumber domain. The response of the soil under torque is determined using Green’s functions. Finally, the comparison of theoretical and simulation results confirms the validity and accuracy of the pile-soil coupling model during pile driving through torsional vibration, based on the analysis of both pile and soil.