Study on horizontal bearing characteristics of pile foundations in coral sand

This paper presents the horizontal bearing characteristics of piles in coral sand and silica sand from comparative experimental studies. Six model piles with different diameters were tested. The horizontal bearing capacity, deformation characteristic, bending moment, p–y curve, change in soil horizontal pressure, as well as particle breakage behaviour of coral sand were investigated. The results show that, in the coral sand foundation, the horizontal bearing capacities of piles and the increments in soil horizontal pressures are obviously greater than those in silica sand. Accordingly, the lateral displacement, rotation of the pile head, bending moment, and corresponding distribution depth in coral sand are significantly smaller than those in silica sand. The p–y curves indicate that the horizontal stiffness of coral sand is greater than that of silica sand. Remarkably, the breakage behaviour of coral sand is mainly distributed in the range of 10 times the pile diameter depth and 5 times the pile diameter width on the side where the sand is squeezed by the pile. Furthermore, in coral sand, the influence of pile size is more pronounced, the squeezing force generated by the pile spreads further, and its influence range is larger compared to those in silica sand.