Dynamic impedances of piles and groups of piles in saturated soils

A three-dimensional boundary element model is presented for the computation of time-harmonic dynamic stiffness coefficients of piles and pile groups embedded in two-phase poroelastic soils. Piles are modelled as continuum elastic solids and soil as a fluid-filled poroelastic half-space governed by Biot's theory. Piles are bonded to the surrounding medium along the contact surface where rigorous pile-soil interaction conditions are imposed. The technique has been applied to the calculation of vertical and horizontal dynamic impedance functions of piles and 2 × 2 pile groups. Selected numerical results are presented to portray the influence of excitation frequency, pile stiffness, porous medium properties and kind of pile-soil contact conditions.