Consolidation of soil induced by pile installation considering disturbance effect

Abstract

In practice, the consolidation of soil around the pile has a great influence on the time-dependent bearing capacity of pile. However, most of the consolidation theory of soil around the pile neglects the disturbance effect of pile-driving on surrounding soil and regards the soil as homogeneous, which overestimates the consolidation efficiency of the soil, and obtains a higher pile bearing capacity. In view of this, a consolidation model of soil around a pipe pile considering soil disturbance effect is presented in this paper. Fourier transform and separation of variables are used to obtain the analytical solution, and then the solution is verified by degradation analysis and Finite Difference Method (FDM). Firstly, the radial and vertical distribution of excess pore pressure generated after pile-driving is analyzed. In the radial direction, the excess pore pressure decreases rapidly from the radius of pipe pile to the radius of the disturbed zone, then slowly decays to 0 from the radius of disturbed zone to the influencing radius of pipe pile. In the vertical direction, the excess pore pressure along the vertical direction grows linearly. Subsequently, the variation of the average excess pore pressure at the pile-soil interface with the permeability coefficient and radius of disturbance zone are analyzed. The permeability coefficient of disturbance zone has a remarkable negative effect on the excess pore pressure during the whole consolidation period. Increasing the radius of the disturbance zone will hinder the dissipation of the excess pore pressure in the intermediate and later stages. Finally, the validity of the proposed analytical solution is illustrated by comparing with the laboratory results.