The 12th International Conference on Scour and Erosion (ICSE 2025)

As offshore wind power construction grows globally, predicting erosion and long-term scour around monopile foundations is crucial. This study examines an offshore site near Chiba Prefecture, Japan, where the seabed consists of a 40-meter-thick sand layer with high organic content. Using the Erosion Function Apparatus (EFA), erosion behavior was assessed at flow velocities up to 7 m/s, focusing on critical shear stress and erosion rates to classify seabed soil. The study revealed that the organic-rich sand had a critical shear stress of 53 Pa and an erodibility coefficient of 35 mm/hr/Pa, indicating strong erosion resistance. Erosion behavior varied significantly with organic content, affecting soil classification and scour predictions. The SRICOS-EFA program estimated maximum scour depths of 1.6 meters for organic-treated soil and 2.9 meters for untreated soil, underscoring the impact of organic material on erosion. These findings are essential for designing offshore wind power structures, demonstrating that organic content in the soil plays a key role in erosion resistance and must be considered in construction planning.

Offshore,Erosion,Offshore wind farms,Modeling,EFA