Seismic Fragility Assessment of a Novel Suction Bucket Foundation for Offshore Wind Turbine under Scour Condition

• Published in: Energies (Basel) 2022-01, Vol.15 (2), p.499
• Main Authors: Ngo, Duc-Vu, Kim, Young-Jin, Kim, Dong-Hyawn
• Format: Article
• Language: English
• Subjects: Buckets; Commercialization; Construction costs; Design; Dynamic response; Earthquakes; Environmental conditions; Fragility; fragility curve; Ocean floor; Offshore; Offshore energy sources; Offshore operations; offshore wind turbine (OWT); scour; Sea level; Seismic activity; Seismic response; Seismic stability; shallow muddy seabed; Suction; suction bucket (SB); Turbines; Wind power
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en15020499

This study proposed a new suction bucket (SB) foundation model for offshore wind turbines (OWT) suitable for a shallow muddy seabed, using more than three single buckets through kinetic derivation. The performance of new optimal foundation was evaluated by its horizontal displacement capacity and compared with a conventional SB composed of three buckets. Under external loads such as earthquakes, wind, and the combination of the both, the stability of this novel SB foundation was verified. The seismic fragility curve was also evaluated at some scour depths. These results were compared with the response of a tripod suction bucket (TSB) foundation, which was also designed for a shallow muddy seabed. The results indicated that scour significantly changed the dynamic response of this novel SB foundation but it had a better bearing capacity than the TSB foundation, despite its smaller size and weight. The fragility of TSB is always higher than the developed foundation in the same environmental condition. With reasonable volume and size, this novel SB foundation has great potential for future industrialization and commercialization.