The response of pile groups under cyclic lateral loads

Numerous pile groups are subjected to significant cyclic lateral loads due to wind, waves or earthquakes, and many have failed catastrophically. In this research, centrifuge modelling of a pile group subjected to cyclic lateral loads has been conducted to investigate the interaction effect in pile groups and the influence of cyclic lateral loads on the performance of pile groups. Different pile installation methods were also applied to capture the full range of construction-induced soil conditions available in the field. Lateral permanent displacements of the pile group were seen to be induced by one-way cyclic lateral loads but not by two-way symmetric cyclic lateral loads. The lateral secant stiffness of the pile group increases slightly with increasing number of cycles, and leading piles attract greater loads than trailing piles. Furthermore, permanent settlements of the pile group accumulate, which can be attributed to the swaying motion of the pile cap induced by cyclic lateral loads.