A method to quantify the beneficial effect of scour protection on lateral behaviour of monopiles for offshore wind turbines

Li, Qiang; Prendergast, Luke; Gavin, Ken; Askarinejad, Amin; Wang, Xinquan

Abstract

To mitigate against scour hole formation, scour protection can be placed around offshore wind turbine monopiles. Few studies have considered the beneficial effect of this geotechnical reinforcement measure on the foundation lateral resistance. The contribution of scour protection to lateral resistance of monopiles in sand is investigated in this paper using centrifuge tests and finite element analyses. Multiple scour protection widths and thicknesses are modelled around a monopile, to identify the most effective scour protection properties at mitigating lateral displacements. Two methods for modelling scour protection effects (one using material, the other using direct overburden pressure) are compared. The lateral response of monopiles with different slenderness ratios under various scour protection widths and overburden pressures are simulated. Results suggest that pile lateral displacements reduce by up to 41% when scour protection with width 2D (D, pile diameter) and applied overburden pressure of 30 kPa is used, compared to no scour protection, for a given test case. A method to modify design approaches to consider the beneficial contribution of scour protection on pile lateral behaviour using an envelope diagram is proposed, which provides relationships for scour protection properties and various monopile slenderness ratios.

Citation

Li, Q., Prendergast, L., Gavin, K., Askarinejad, A., & Wang, X. (2024). A method to quantify the beneficial effect of scour protection on lateral behaviour of monopiles for offshore wind turbines. Ocean Engineering, 307, Article 118196. https://doi.org/10.1016/j.oceaneng.2024.118196

• Journal Article Type: Article
• Acceptance Date: May 13, 2024
• Online Publication Date: May 21, 2024
• Publication Date: Sep 1, 2024
• Deposit Date: May 21, 2024
• Publicly Available Date: May 22, 2025
• Journal: Ocean Engineering
• Print ISSN: 0029-8018
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 307
• Article Number: 118196
• DOI: https://doi.org/10.1016/j.oceaneng.2024.118196
• Public URL: https://nottingham-repository.worktribe.com/output/35148541
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0029801824015348?via%3Dihub