Static and cyclic p-y curves for laterally loaded piles in soft clay

A pseudo-three-dimensional analysis method on static p-y curves of laterally loaded piles in soft clay is conducted. This method is based on the two-dimensional elastic fictitious loading upper bound limit analysis approach considering the stress-strain relationship of soils and the improved profile of three-dimensional ultimate bearing capacity. The cyclic p-y curves of laterally loaded piles are established by combining the static p-y curves of laterally loaded piles considering the soil characteristics, the Masing criterion and the relationship between the undrained shear strength and the cumulative plastic displacement of soils. Published centrifuge model tests are analyzed with the proposed p-y curves simultaneously considering the soil stress-strain relationship and strength degradation. The results show that the proposed method can simulate the static and cyclic behavior of laterally loaded piles in clay with reasonable accuracy. After being calibrated with model tests, the proposed cyclic p-y curve can be applied in the analysis of laterally loaded piles. Under different cyclic loading amplitudes, the hysteresis load-displacement curves at pile top and the corresponding degradation curves of the mobilized load at pile top obtained by the proposed cyclic p-y curve are similar to those observed from the centrifuge experiments.