Investigation of the torsional behaviour of circular piles in double-layered nonhomogeneous soil

Response of piles subjected to torsional loading is significantly affected by soil profile and the interaction between soil and pile, which has not yet been fully understood. This paper describes a new analytical method for predicting the nonlinear response of torsional loaded piles in a double-layer soil profile, which considers the effect of elastoplastic behaviour of soil and the nonlinear variation of soil profile. The results from the new method have been compared with experimental and other published data, with good agreement obtained. Finally, an illustrative example has been carried out to explain how the new method can be applied to a practical situation.