The tension capacity of suction bucket foundations in sand – a centrifuge experimental study

This paper presents the results of centrifuge model tests on bucket foundations conducted in clean silica sand to simulate the loading conditions which apply at the windward leg of a three-legged offshore wind turbine jacket structure. Load sharing response between bucket skirt and soil, and the concurrent suction pressure under the bucket lid, was analysed for tests conducted under different drainage conditions and (simulated) water depths. In addition, the deduced bucket skirt resistance during cyclic loading (under the same drainage conditions and water depths) is compared to the monotonic drained vertical pull-out resistance, in order to assess the evolution of skirt resistance during cyclic tensile loading, and to identify the relative contributions of suction pressure and skirt resistance to the overall suction bucket cyclic load response.