effects of cyclic and post-cyclic loading on lateral response of flexible piles embedded in dry sand

This study aims to investigate the response of flexible piles in the course of cyclic and post-cyclic lateral loadings for different loading scenarios including cyclic loading pattern, loading frequency, and also amplitude. for this purpose, an experimental program has been organized and a series of tests were conducted on a model pile embedded in dry sand. experimental p–y curves derived from bending moment profiles for different loading patterns, namely symmetric two-way, asymmetric two-way, full one-way, and one-way patterns without complete unloading were studied. the results indicate that the stiffness is highly dependent on the cyclic loading pattern, and the two-way cyclic loading was found to increase the lateral force and soil stiffness more than any other factor. also, compared to the monotonic loading, the residual force induced by one-way loading and one-way loading without complete unloading causes the lateral bearing capacity to decrease significantly. in addition, the post-cyclic load–displacement response of the pile was found to be influenced by the number of cycles, loading amplitude, and soil density index. finally, a comparative study revealed that predictions made by the api code for the lateral resistance of flexible piles embedded in dry sand underestimate the p–y curves obtained from experimental observation. © 2022, iran university of science and technology.