Author(s): Yuhang Zhang; Jinfeng Zhang; Zhengqi Li; Tongqing Chen; Qinghe Zhang; Jiandong Xiao
Linked Author(s): Jiandong Xiao
Keywords: Local scour; Offshore wind turbine foundation; Mono-column composite bucket foundation; Physical experiment; Wave-current interaction
Abstract: The issue of seabed scour around offshore wind turbine foundations is a significant safety concern. In this study, local scour around a specific type of foundation, known as the large-diameter Mono-Column Composite Bucket Foundation (MCCBF) with six connectors, has been investigated through physical experiments in the flume. The study involved various flow conditions, including unidirectional flows, tidal flows, and combinations of regular waves and currents, and two flow directions (0° and 30°) were considered. The geometric scale was chosen as 1:50, while the plastic model sand for experiments was selected based on the similarity of sediment critical velocity and settling velocity. The development of scour and equilibrium scour topographies were measured using an ADV on the 3D guideway positioning system. It was observed that the flow direction of 0° always results in a greater scour depth compared to 30°, primarily due to the varying effects of connectors on the flow dynamics. The scour depth under tidal flow accounts for approximately 77% to 96% of that under unidirectional flow. As the flow intensity increases, the scour depth under these two flow conditions becomes closer. Compared to unidirectional flow, both the scour range and depth increase significantly under wave-current interaction. Based on the results, an empirical formula (R2=0.902) was derived to predict the on-site maximum scour depth for the MCCBF.
Year: 2024