Behavior of pile subject to negative skin friction and axial load

Centrifuge model tests have been conducted to investigate the effect of negative skin friction on piles installed through soft clay and founded in underlying dense sand. The first test series involved the study of fundamental mechanism of piles subject to negative skin friction only. In these tests, negative skin friction was induced by self-weight consolidation of clay followed by in-flight sand surcharge placement on the clay. The second test series examined the behavior of piles subject to simultaneous negative skin friction and axial load. The effects of axial load on the load-transfer characteristics along a pile experiencing locked-in negative skin friction induced by consolidating clay are investigated in detail in this paper. The effects of pile tip condition (end-bearing or socket pile), pile socket length and magnitude of applied load on the pile are also studied.