Centrifuge modelling of spudcan-pile interaction in soft clay overlying sand

When a jack-up rig is installed in close proximity to an existing piled jacket platform, the massive soil movements induced by spudcan penetration may damage the adjacent piles. In 2012 the authors reported the findings of an extensive centrifuge model study on spudcan-pile interaction in soft clay. As a seabed profile may consist of soft clay over stiff soils and the spudcan-pile interaction phenomenon in such case is expected to be significantly different from that in soft clay, the earlier study is extended to investigate the interaction of a spudcan with adjacent piles in a soft clay overlying sand profile. Besides centrifuge tests on model spudcans, tests on half-spudcans placed behind the transparent window of the model container have been conducted to evaluate the soil movements and failure mechanism for various model configurations and soil conditions. The experimental results and findings are presented in this paper.