Seismic risk-based assessment of acceleration demands on a reference 10-MW jacket-supported offshore wind turbine under combined horizontal and vertical excitations
File(s)
Published version
Author(s)
Khalil, Zeyad
Stafford, Peter J
Elghazouli, Ahmed Y
Type
Journal Article
Abstract
Offshore wind energy is increasingly recognised as a vital source of renewable energy worldwide, with offshore wind farms currently being operated and developed in regions of moderate to high seismic activity. However, there is still limited data on how large-scale offshore wind turbines perform during earthquakes, highlighting the need for further research. This study focuses on the assessment of the seismic performance of large-scale jacket-supported offshore turbines, which have received less attention compared to monopile-supported turbines, and can offer a more attractive solution in seismic regions. Using a risk-based approach, this study investigates the seismic acceleration demands at the rotor-nacelle assembly (RNA) level for a four-legged, X-braced reference steel jacket structure supporting a 10-MW turbine, acting as a representative example of existing and future large-scale jacket-supported offshore wind turbines. The structure is assumed to be located in a reference site in a highly seismically active region, where the hazard is driven by different source types. Particular focus is given to the associated hazard-consistent ground-motion selection methodology considering combined horizontal and vertical ground-motion excitation at different seismic intensity levels that is required for the proper evaluation of the structural system response. 300 nonlinear response history analyses are conducted where the performance is evaluated against a representative range of RNA acceleration limits for which conditional fragility curves are developed. Moreover, to aid in further damage and loss assessments of such structures, a demand curve showing the annual rate of exceeding different demand values is reported. In addition, the contribution of higher-mode response including vertical system excitation is discussed. Finally, in order to relate the acceleration demands to potential structural damage levels, buckling strength evaluations for the support tower are presented and discussed.
Date Issued
2025-11-01
Date Acceptance
2025-08-22
Citation
Bulletin of Earthquake Engineering, 2025, 23 (14), pp.6047-6081
ISSN
1570-761X
Publisher
Springer
Start Page
6047
End Page
6081
Journal / Book Title
Bulletin of Earthquake Engineering
Volume
23
Issue
14
Copyright Statement
© The Author(s) 2025 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
10.1007/s10518-025-02271-1
Publication Status
Published
Date Publish Online
2025-09-05