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

Abstract

Summary This paper conducts a comprehensive study on the effects of expansion force after pile driving on the vertical vibration of the hollow pile. The initial radially inhomogeneous strain field of soil in disturbed soil region and dynamic shear modulus of remolded soil are constructed by applying the cylindrical cavity expansion method. The equation governing the incremental motion of the soil is consequently deduced on the basis of incremental deformations superposed on an underlying finite deformation. The longitudinal impedance of the top of the pile and the velocity response in frequency and time domains are also numerically studied. The relations between the expansion force after pile driving and the velocity response of the pile with different wall thickness are discussed accordingly. The results suggest that a pile has a better dynamical stability when the characteristics of the section are optimized and interacting force with soil medium gets smaller.

Vertical frequency‐domain compliance of an elastic pipe pile embedded in a liquid‐filled and porous‐viscoelastic soil

“…The particular solution of Equation ( 9) can be obtained by using Equation (30), and then adds the homogeneous solution Equation ( 12) to obtain the complete solution for the pipe pile displacements as follows:…”

“…[18][19][20][21][22][23][24][25][26][27][28][29] The frequency-domain dynamic impedances of pipe piles in single-phase soils subjected to vertical time-harmonic loadings were obtained to evaluate the pile bearing capacity or dynamic characteristics. Moreover, the pile bottom conditions can be divided into four types: (1) free and unsupported pile bottom 30,31 supported by springs and dashpots 32-40 ; (3) half spaces at pile bottom [41][42][43] ; (4) rigid bedrock support at pile bottom. [44][45][46][47] In fact, the frequency-domain impedance function in these studies also can be used to derive the time-domain velocity response for integrity testing through the convolution theorem.…”