Experimental Studies on Modified Suction Caissons in Fine Sand Subject to Uplift Loading

Abstract

A modified suction caisson (MSC), which was reported by the authors of this paper previously, comprises an external short-skirted structure that is added to a regular suction caisson (RSC). It has been proved that MSCs can improve the lateral bearing capacity and limit the deflection of the caisson compared with RSCs. A series of model tests were conducted to investigate responses of MSCs subject to uplift loading in saturated sand. The effects of external skirt dimensions on the uplift bearing capacity of MSCs were considered. In addition, the influences of the sealed top lid of the skirted structure on the uplift bearing capacity and the resulting passive suction of MSCs were also studied. It was found that the uplift bearing capacities of MSCs are 1.4–1.7 times that of RSCs. Moreover, test results in serviceable conditions show that the sealed external skirted structure of perspex-made suction caissons significantly contributed to the uplift bearing capacity as a result of passive suction.

Keywords

Offshore wind turbine / Modified suction caisson / Uplift capacity / Fine sand

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