Laterally loaded piles and pile groups partially embedded in transversely isotropic fractional viscoelastic saturated soils

Abstract

This paper investigates the time-dependent behaviour of laterally loaded piles and pile groups partially embedded in stratified transversely isotropic (TI) saturated soils. The partially embedded single pile in stratified soils is regarded as a Timoshenko beam, and its total stiffness matrix can be assembled by using the finite element method (FEM). Based on the fractional viscoelastic model for solving non-axisymmetric consolidation of stratified cross-anisotropic media developed before, the solution for a partially embedded single pile is obtained by combining the boundary element method (BEM) and the extended precise integration solution of the media. Considering the interaction between piles in a pile group and the load distribution from the pile cap to pile tops, the solution for the partially embedded pile group is derived by extending the solution of single piles. The accuracy and efficiency of the proposed solution is verified with existing literatures, and some examples are designed to investigate the effects of the embedment ratio, the transverse isotropy, the slenderness ratio, the fractional derivative order, the flexibility coefficient and the pile spacing. Numerical results show that the embedment ratio and fractional derivative order are essential parameters that significantly affect the rate of the time-dependent response of the partially embedded lateral loaded piles.