Exact Solution for the Torsional Vibration of an Elastic Pile in a Radially Inhomogeneous Saturated Soil

Xibin Li,Zhiqing Zhang,Jianchao Sheng,Zhaoqing Wang

doi:10.1155/2021/6644057

Xibin Li, Zhiqing Zhang + Show 2 more

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https://doi.org/10.1155/2021/6644057

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Abstract

An exact solution is proposed to study the time-harmonic torsional vibration of an elastic pile embedded in a radially inhomogeneous saturated soil. The radially inhomogeneous saturated soil is composed of inner disturbed and outer semi-infinite undisturbed concentric annular regions, with the shear modulus of the inner region changing in an exponential form along the radial direction. The governing equation of each region of the saturated soil is solved through rigorous mathematical derivation and the soil torsional impedance is derived with an exact and explicit expression. Making use of the boundary and continuity conditions of the pile-soil system, the torsional complex stiffness at the pile top is obtained in an exact closed form in the frequency domain. Selected numerical results are presented to investigate the influence of the radial inhomogeneity of the surrounding soil on the vibration characteristics of the pile-soil system.

Highlights

Soil-structure dynamic interaction problem, including the interaction between a loaded rigid disc and the adjacent soil and the interaction between the pile and surrounding soil, has been the subject of extensive studies in civil engineering for many years
Pak and Abedzadeh [3] used boundary integral technique to determine the reaction of the soil and proposed the solution for the rigid circular disc under time-harmonic torsional load
For the pile-soil dynamic interaction problem, the analytical method [4, 5] and numerical method [6] are developed to solve the torsional vibration of an elastic pile embedded in a homogeneous or layered soil medium

Summary

Introduction

Soil-structure dynamic interaction problem, including the interaction between a loaded rigid disc (footing) and the adjacent soil and the interaction between the pile and surrounding soil, has been the subject of extensive studies in civil engineering for many years. For these interaction problems, the establishment of a dynamic model of the soil medium and the corresponding solution is the key to study the vibration characteristics of the soil-structure system. Pan et al [1] and Zhang and Pan [2] used fundamental solutions of the surface/buried annular patch torsional load on/in the soil medium and solved the dynamic impedance of the rigid circular disc via integral least-square approach. In actual engineering, no matter precast piles or cast-in-place piles, they are bound to disturb or squeeze the surrounding soil in a certain range during the construction process

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