Dynamic pile-head stiffness of laterally loaded end-bearing pile in linear viscoelastic soil − A comparative study

Abstract

An approximate analysis following the Vlasov-Leontiev foundation model is developed to evaluate the pile-head stiffness (static and dynamic) of laterally loaded end-bearing pile, embedded in a homogeneous, isotropic, and linear viscoelastic soil with frequency-independent hysteretic material damping. In the analysis, the pile is modeled – a Euler-Bernoulli beam and the soil – a continuum. The horizontal soil displacement fields because of the pile motion is mathematically expressed as a product of separable functions while the vertical soil displacement is ignored for the sake of mathematical simplicity. The contribution of vertical soil displacement on the lateral response is indirectly included in the analysis by a modification of the soil modulus. The Extended Hamilton’s principle is applied to obtain the differential equations governing pile and soil motions, which are solved analytically following an iterative algorithm. The degree of accuracy, and the capability of the analysis to capture the essential mechanics (particularly because of dynamic loading) is assessed by comparing static and complex dynamic pile-head stiffness against other popular analyses developed in the literature. Based on the comparisons, appropriate discussions on the present, and analyses available in literature are provided; further, recommendations on the advantages of this analysis for use in practice are also outlined.