SCOUR AROUND AND SINKING OF SUBSEA STRUCTURES EXPOSED TO CURRENT AND WAVES

Many different subsea structures are used in the offshore industry, particularly for floating offshore wind farms, such as gravity anchors, tensioners, clump weights, and chains. Exposure of a subsea structure to currents and/or waves leads to changes in flow around the structure, forming flow contraction at the sides of the structure and secondary flow patterns such as horseshoe vortices, lee-wake vortices, and counter-rotating vortices (Sumer and Fredsøe, 2002). Often placed on erodible beds under current and/or wave action, scouring around these structures are experienced. The present paper presents the early results of an experimental study aiming to investigate the aforementioned scour and sinking processes around cuboid blocks (cubes, rectangular prisms and horizontal cylinders) under the action of waves, currents, and waves combined with currents.