Cyclic p-y curve model of unidirectional loaded pile in sand considering the characteristic of friction in the strain wedge model

Abstract

Pile foundations are always subjected to cyclic loads due to the action of wind and waves. A cyclic p-y curve model considering the characteristic of friction force is proposed to study the lateral response of pile foundations under unidirectional cyclic loads in sand. The soil resistance calculated by the improved nonlinear strain wedge model (SWM) is divided into friction resistance and compression resistance according to the different characteristics of soil resistance. The friction resistance depends on the relative displacement between pile and soil, whose direction and magnitude will constantly change in the process of cyclic load, while the compression resistance is analyzed by combining the extended Masing rule and soil degradation model. The validity of the model proposed in saturated sand is verified by centrifuge test results. Furthermore, the influence of cyclic loads on pile deflection, bending moment and soil resistance is analyzed through the results calculated by the cyclic p-y curve model.