Approach for a floating pile embedded in poroelasitc soil under horizontal dynamic load

Abstract

The deformation mechanism in the horizontal direction of a floating pile under dynamic load should be paid extensive attention. The closed-form solution of dynamic characteristics of a floating pile in poroelasitc soil subject to horizontal dynamic load is obtained by a newly developed framework in this paper. Firstly, based on the three-dimensional continuum model and Biot’s poroelastic theory, the governing equations of the pile surrounding soil and pile end soil are respectively established. Secondly, the pile shaft reaction is calculated by use of the conventional method used in many existing literatures, and the pile base resistance is obtained with the aid of the Hankel transform technique and mixed boundary-value conditions that came from the contact interaction between a rigid massless disk with its beneath soil layer of finite thickness. Thirdly, the Timoshenko beam theory is applied to depict the pile vibration considering its shear deformation, and thus the dynamic impedance functions at pile head are derived. Subsequently, the correctness of the proposed solution is verified through comparisons with the existing results from other scholars. Finally, a parameter analysis about the thickness of the pile end soil, pile slenderness ratio and soil permeability are performed. Results suggest that the soil layer thickness and pile slenderness ratio have a pronounced effect on the pile dynamic behavior, and considering the soil permeability is more realistic to pile vibration response. The obtained results can exert great significance to the serviceability of floating pile for engineering practice.