Numerical analysis of seabed dynamic response around a four-bucket jacket foundation under combined wave-current loading

Transient seabed liquefaction adjacent to marine structures under combined wave-current loading threatens offshore infrastructure stability. To address this, numerical investigations of wave-current-structure-seabed interactions are performed for a four-bucket jacket foundation using the open-source CFD platform OpenFOAM. This study systematically analyzes dynamic seabed responses and maximum transient liquefaction depths around the structure, with particular emphasis on wave height, wave period, current velocity/direction, and inter-bucket spacing. Key results reveal that maximum liquefaction depth increases with wave height/period and co-directional current velocity, yet decreases with reduced bucket spacing. Wave height dominates as the primary influencing factor. Furthermore, the spatial distribution of liquefaction depth around the foundation intensifies initially before gradual attenuation under combined wave-current conditions. Notably, forward-positioned buckets exhibit significantly higher susceptibility to liquefaction than rearward buckets. These findings offer valuable insights for stability assessment and protective design of offshore bucket jacket foundations.