Closed-form formulation for the response of single floating piles to lateral dynamic loads

Abstract

This paper presents a mathematical model that provides the response to lateral dynamic loads of single floating piles embedded in a homogeneous viscoelastic soil layer. The formulation results in closed-form expressions of the pile’s swaying, rocking and cross swaying-rocking compliance components, that do not require solving complex integral equations or iterative calculations. The model exploits Tajimi’s elastodynamic theory to compute the dynamic soil resistance to pile movements. One of its main features is allowing for the effect of the thickness of the soil layer on the response of the soil-pile system, by properly accounting for resonance effects associated with the formation of standing waves. The model is validated by comparing its results for the special case of a floating pile embedded in elastic half space against published analytical and numerical results. The paper concludes with a parametric study, focused on exploring under which conditions standing waves may result in “softer” response of the soil-pile system, a phenomenon that may be important for the serviceability analysis of foundation systems sensitive to resonance effects.