Centrifuge tests of axially loaded piles in consolidating soil

Axially loaded piles installed in layered soils where the upper soil layer is still consolidating are subjected to the combined interactive action of axial load and drag load. The shift of the location of the neutral plane as a result of the interaction of the axial load and drag load leads to the possibility that such piles need not account for the negative skin friction in determining the maximum pile force for the pile structural design. The results of a series of centrifuge tests on axially loaded piles in consolidating layered soil are presented so that the effect of negative skin friction on pile settlements and locations of the neutral plane of such piles can be better understood. The criteria regarding whether negative skin friction needs to be accounted for in determining the maximum pile force for the pile structural design are established in the present study based on centrifuge test results and findings reported in the literature.