Centrifuge Model Study on the Effect of Lattice Leg and Sleeve on the Postconsolidation Bearing Capacity of Spudcan Foundation

Abstract

Up to now, the postconsolidation bearing capacity enhancement of jack-up spudcan foundation has been explored using centrifuge model tests and numerical analyses, which however ignored the realistic jack-up lattice leg. This paper investigates both typical lattice leg and sleeve effects on the postconsolidation spudcan bearing capacity using centrifuge model tests, by replicating the entire process of spudcan in normally consolidated clay: “penetration–unloading–consolidation–repenetration.” The experimental results show that the lattice leg and sleeve affect the spudcan bearing capacity in two sides compared with spudcan without leg. First, it increases the transient bearing capacity during initial spudcan penetration; second, less postconsolidation bearing capacity improvement is yielded by the presence of the leg. The former effect is of importance on the prediction of jack-up leg penetration, and the latter effect would suggest a lower risk of spudcan punch-through for realistic offshore jack-up rig during preloading and operation period.