Torsional vibrations of single piles embedded in saturated medium

From the axisymmetrical point of view, the dynamic response of single piles vertically embedded in the saturated half space and subjected to harmonic torsional loadings is investigated by means of integral transform and Muki’s methods for the first time. By treating the pile as a one-dimensional bar and the half space as a three-dimensional poroelastic continuum, the dynamic interaction between the pile and poroelastic medium is formulated in a Fredholm integral equation of the second kind. Numerical results are presented to illustrate the influence of pile flexibility, geometrical properties of pile–saturated soil system and frequency of excitation on the pile’s torque, torsional angle and coupled impedances. The conclusions obtained can serve as guidelines for the design and dynamic pile testing of practical engineering.