Centrifuge model study on spudcan extraction in soft clay

Abstract

Operators of mobile jack-up rigs often face difficulties when extracting spudcan foundations of jack-up rigs with deep leg penetration particularly in soft clay. Besides posing a vulnerability to the jack-up structure, this problem also causes significant economic consequences to the offshore industry. The scarcity of specific studies in this area makes the understanding of the spudcan extraction problem remains unclear. In the present study, centrifuge model tests were carried out to provide a fundamental understanding of spudcan extractions specifically in normally consolidated clay. The experimental study involved the quantification of uplift resistance and its contributing factors, and the evaluation of the breakout failure mechanism. Based on the major findings an improved spudcan extraction method was proposed and evaluated in laboratory conditions.