Longitudinal dynamic response of pile foundation in a nonuniform initial strain field

Abstract

This paper presents an investigation into the dynamic response of pile and soil due to pile installation in a radially inhomogeneous initial strain field. The radial variation rule for the shear modulus and physical parameters of the soil caused by the initial strain field is deduced. On the basis of the plane strain and complete P-S (pile-soil) contact assumptions, the analytical solution of longitudinal dynamic impedance of the soil is derived by means of subdividing the soil domain into a number of annular vertical zones. The longitudinal impedance of the pile top and velocity response in frequency and time domains, are also obtained. The parametric study of interfacial pressure on the dynamic response of P-S system is undertaken within a relatively lower frequency domain. Comparison results between previous solutions and the present study indicates that the analytical solution derived in this paper is more stable.

On vertical dynamic stability and cross‐section optimization of closed‐ended hollow pile by considering soil compaction effects

“…As can be seen from Figure , these trends are triggered mainly by reduced dynamic shear modulus μ e . The verification of the relation between expansion force and impedance properties of porous soil has been done in Tian et al Since the present solution for elastic soil is a special case of the porous medium (let the porosity being zero), our results are in good agreement with those in previous studies.…”

“…To obtain a stable solution, choosing an appropriate subdivision number is a key step. According to Tian et al, the value of m ′ in present study is chosen to be 200 and the outer boundary of annular disturbed soil zone r e is defined as 6 times the radius of the pile.…”

“…In this paper, the variation function of dynamic shear modulus, which was developed by Tian et al on the theory of .incremental deformations superposed on an underlying finite deformation, is extended to investigate the frequency‐dependent performance of hollow pile. The motivation for choosing the hollow section to be the subject investigated is its evident advantage in static bearing capacity and unclear dynamic character.…”

“…Other investigations on the vertical vibration of the pile were focused on the influence of wave effects, 13 weld characteristics, 14 construction disturbance, 15 or variation in cross section. 16 It seems that the first attempt to attributed the variation of shear modulus of disturbed soil to the expansion force after pile driving was made by Tian et al, 17 in which the variation function of shear modulus of soil was rigorously deduced from the theory of incremental deformations superposed on an underlying finite deformation. 18 In view of those findings, the true mechanism of the variation of dynamical modulus of soil is poorly understood, mainly because of the difficulties in the instantaneous measurement of the strain-dependent shear modulus of soil.…”

Vertical vibration of a large diameter pile embedded in inhomogeneous soil based on the Rayleigh-Love rod theory

“…This phenomenon not only affects the bearing capacity of the pile (El Naggar and Wei, 2000;Liu et al, 2010;Gong et al, 2012;He et al, 2015), but also has an impact on the dynamic behavior of the pile (Han, 1997;El Naggar, 2000;Yang and Tang, 2013;Tian et al, 2015).…”