Lateral Pile Interaction Factors in Submerged Sand

Abstract

Groups of laterally loaded piles can be analyzed for displacement and distribution of loads among the piles heads by means of a stiffness matrix equation that incorporates individual pile stiffnesses and the influences of piles on their neighbors using pile‐head interaction factors. To date, only analytically derived interaction factors were available for laterally loaded pile groups; however, in the study reported herein lateral interaction factors for groups of free‐ or pinned‐headed piles were determined from full‐scale experiments in submerged sand. The measured factors tended, on the average, to validate factors that had been derived analytically by others. However, interaction between any two piles was found to be strongly dependent on the relative position of the piles to an extent that reciprocity could not be inferred. The interaction factors also increased with increasing magnitude of load and decreased with increasing numbers of cycles of load.