Development and Field Verification of a Scour Reduction Technique for Offshore Wind Suction Foundations Using Artificial Seaweed Mats

In response to global initiatives addressing climate change and achieving carbon neutrality, offshore wind power has gained significant attention. Consequently, the utilization of suction foundations adaptable to various seabed conditions has been expanding. Suction foundations are increasingly recognized as an advantageous foundation type for marine structures due to their rapid installation, environmental friendliness, and reusability. However, the large-diameter characteristics of such structures make them vulnerable to local scouring caused by flow variations around the seabed, posing a potential threat to structural stability. In particular, suction foundations are inherently susceptible to scour, necessitating effective mitigation measures.</br>Conventional physical protection methods, such as gabions, concrete mattresses, and armor blocks, have been commonly used for scour prevention but exhibit limitations in constructability, maintenance, and ecological impact. Therefore, there is a growing demand for eco-friendly scour reduction technologies that consider both structural and environmental aspects.</br>This study proposes a scour mitigation method employing artificial seaweed mats that reduce flow velocity and suppress vortex formation around structures. The artificial seaweed mats not only provide hydrodynamic benefits but also serve as habitats for marine organisms, offering a sustainable solution that enhances both structural stability and ecological value. To evaluate the scour reduction performance of the artificial seaweed mat, the structural stability analysis was conducted assuming that the mat is installed around a suction bucket foundation with a height (H) of 6.0 m and a diameter (D) of 5.0 m, while the outer diameter of the seaweed mat was set to three times the bucket diameter (3×D = 15.0 m). For the scaled physical model tests under near-field offshore conditions, a suction bucket model with a height of 3.0 m and a diameter of 0.6 m was used, and the outer diameter of the seaweed mat was similarly set to approximately three times the bucket diameter (3×D = 1.5 m). Comparative analyses were performed to investigate scour development under various design configurations, including the presence or absence of the proposed method, mat dimensions, and artificial seaweed arrangement patterns. The results aim to support the development of an artificial seaweed-mat scour mitigation technique that enhances structural stability while simultaneously considering marine environmental protection, ultimately enabling its application to suction-bucket foundations used for offshore wind turbines.