The Influence of Cylic Loading Frequency on the Behaviour of Suction-Bucket Foundations for Offshore Structures

The behavior of suction-bucket foundation systems for offshore structures has not been adequately investigated yet. The foundations are subjected to large cyclic loading due to marine conditions which lead to accumulation of soil deformation and excess pore water pressure. A numerical investigation was conducted to study the response of one bucket support of a multipode foundation system under cyclic axial loading. Thereby a fully coupled two-phase model and a hypoplastic constitutive model were used for consideration of accumulation effects in a saturated soil medium. Special emphasis is attached to the influence of cyclic loading frequency on the behavior of the bucket-soil system. The results have indicated that the frequency considerably affects the excess pore water pressure development and the vertical displacement accumulation of the bucket foundation.