Stability Study on the Bucket Foundation with Multi-Compartment During the Floating-up Process Considering Air Compressibility

In the process of developing offshore wind power towards deeper waters, the advantages of the bucket foundation in terms of integrated construction and economy are becoming increasingly evident. In contrast to conventional floating bodies, the air-floating bucket foundations can achieve self-floating with the help of the air in the compartment and adjust its buoyancy and stability by controlling the air volume in the compartment. The construction process of the bucket foundation involves the control of air in the compartment, thus making it more difficult to construct. Especially after the prefabrication of the bucket foundation, the stability of the bucket foundation at the floating-up stage is particularly critical. The stability of a multi-compartment bucket foundation during the floating-up process cannot be accurately evaluated as the existing theoretical method of air-floating structures does not adequately consider air compressibility. To ensure the safety of the floating-up process, a theoretical method based on the idea of intact stability has been developed to analyze the stability of the air-floating bucket foundations, which will allow accurate calculation of the righting arm for different tilt states and critical air leakage angle. At the same time, accuracy and feasibility of the proposed theoretical method are verified through indoor model tests and practical operation of the prototype structure during the floating-up process. In addition, measures to enhance the stability of the bucket foundation are proposed through sensitivity analysis of influencing factors.