Modeling Clear-Water Scour around the High-Rise Structure Foundations (HRSF) of Offshore Wind Farms

Xiao, Y.; Jia, H.; Guan, D.; Liang, D.; Yuan, S., and Tang, H., 2021. Modeling clear-water scour around the high-rise structure foundations (HRSF) of offshore wind farms. Journal of Coastal Research, 37(4), 749–760. Coconut Creek (Florida), ISSN 0749-0208.The high-rise structure foundation (HRSF) has been used in building the Donghai offshore wind farm in Shanghai, China. So far, few published studies can be found on the local scour around an HRSF. This study presents the results of a physical modeling investigation of the clear-water scour around two typical HRSF models consisting of eight piles and 10 piles, respectively. In the study, the flume bed was covered with uniform noncohesive sediment and the incoming flow was steady. The effects of the alignment angle of the HRSF, water depth, and relative sediment size on the equilibrium scour depth were analyzed. Results showed that the maximum scour depth always occurred around the middle piles on the shoulders of the HRSF. The alignment angle of the HRSF had little influence on the final equilibrium scour depth. For permeable multipile foundations, the scour depth increased when the water depth increased within the range of the testing conditions, which indicates a similar trend between a multipile foundation and a monopile. An empirical formula is proposed for estimating the equilibrium scour depth.