A STUDY ON LONGITUDINAL PILE VIBRATION IN SATURATED LAYERED SOIL AND ITS APPLICATION

A simplified model of longitudinal pile vibration in saturated layered soil is developed using Winkler foundation model to simulate the interaction of soil layers. The solutions of saturated soil layer are derived by means of decomposition of displacement potential and separation of variables. And the coupled dynamic solutions of an arbitrary pile segment are obtained in terms of perfect contact hypothesis on the shaft surface. Then, the analytical solutions in frequency domain and the semi-analytical solutions in time domain at pile head are presented based on the theory of complex resistance transmission. Furthermore, the rationality of the above model and effects of the soil parameters on dynamic responses at the pile head are analyzed. Finally, a field dynamic pile testing is used to verify the validity of the layered model. The results show that the present model is better than the single layer model.