Study on the interaction between pile and soil under lateral load in coral sand

In complex marine environments, research on the response of single piles to lateral loads under different coral sand grain sizes and different embedment depths of the pile body is relatively limited. This study employed indoor scaled-model tests combined with PIV technology, focusing on two variables: coral sand particle sizes and embedment depths of rigid piles. The effects on the bending moment of single piles, the resistance of coral sand, and the displacement of the pile shaft and pile top in coral sand layers were analyzed. The study also revealed the distribution and development patterns of horizontal strain in coral sand particles around the pile top when subjected to lateral loads. The results showed that, as particle size decreased, the maximum bending moment of the pile and the resistance of coral sand increased, the rotation point of pile displacement rose, and pile top displacement increased. In addition, smaller particles had weaker interlocking, resulting in less effective force chain transmission and lower load diffusion. When the embedment depth of the rigid pile decreased, lateral loads could not be transferred to deeper soil layers, leading to more noticeable displacements at the pile shaft and pile top.