Analytical Solution of Horizontal Dynamic Response of a Floating Pile Embedded in an Elastic–Poroelasitc-Layered Soil

Abstract

The horizontal dynamic interaction problems of a floating pile with soil have received little attention from scholars in recent years. This paper first proposed an analytical solution for the dynamic characteristics of the floating pile subjected to horizontal steady-state excitation embedded in soil containing the groundwater table level. Based on Biot’s elastodynamic theory, the governing equations of the soil around the pile are obtained. By virtue of the Hankel transform technique and variable separation method, the shaft reactions and base resistances transferred from the soil are calculated and substituted into the dynamic equation of the floating pile derived by the Euler beam model. The dynamic impedance coefficient of the pile head in the frequency domain is obtained by using the transfer matrix method. Comparisons with the previous studies are performed to validate the accuracy of the presented approach. The effects of the thickness of the pile end soil, the slenderness ratio of the pile, the groundwater table level and the relative modulus of pile material on the pile dynamic response are investigated through several numerical analyses. The results show that there is an “active soil thickness” for the horizontal dynamic forced floating piles due to the reflection and refraction of the stand waves. Meanwhile, the effect of the groundwater table level should not be neglected to ensure the safety of pile foundation under service life.