INVESTIGATIONS ON SCOUR DEVELOPMENT AROUND A GRAVITY FOUNDATION FOR OFFSHORE WIND TURBINES

Mayumi Wilms, Arne Stahlmann, Torsten Schlurmann

Abstract


Due to insufficient insights about the scour development around the STRABAG gravity foundation, the Franzius-Institute conducted small- and large-scale physical model tests in wave flumes on a scale of 1:50 and 1:17 in order to investigate the wave-induced scouring phenomena around the foundation and to design a scour protection system. The tests on scour development without a scour protection system show that the main areas which are vulnerable to scour are the contact areas of the foundation. Furthermore, the experiments show that a scour protection system is necessary for the given and investigated wave boundary conditions; the performance of the selected protection system using geotextile sand containers is verified. Additional numerical simulations indicate an amplification of the resulting flow around the foundation under combined loads (waves and current), but without significant change of the flow pattern

Keywords


scour; scour protection; offshore wind turbines; gravity based foundation, CFD

References


Stahlmann, A. and Schlurmann, T. 2012. Investigations on Scour Development at Tripod Foundations for Offshore Wind Turbines: Modeling and Application. Proceedings of the Coastal Engineering Conference, No. 33.

Sumer, B.M., and Fredsoe, J. 2002. The Mechanics of Scour in the Marine Environment, World Scientific Publishing Co. Pte. Ltd.

Wahrmund, H., Wilms, M., Stahlmann, A., Heitz, C., Schlurmann, T. 2011. Scour development and design of scour protection systems for a gravity based foundation for offshore wind turbines (Kolkbildung und Dimensionierung des Kolkschutzes eines OWEA-Schwerkraftfundaments), 8. FZK-Kolloquium – Maritimer Wasserbau und Küsteningenieurwesen, Forschungszentrum Küste, S. 93-104, 10. March 2011, Hannover (in german)

Werth, K., Wilms, M., Peters, K., Stahlmann, A., Schlurmann, T. 2012. Offshore Wind Turbine Foundations - Hydrodynamic investigations, design, installation and durability of scour protection systems made of geotextile sand-fillled containers, 12th Baltic Sea Geotechnical Conference, Infrastructure in the Baltic Sea Region, Rostock, Germany, pp. 310-316, 31.05.-02.06.2012.

Wilms, M., Wahrmund, H., Stahlmann, A., Heitz, C., Schlurmann, T. 2011. Scour development and design of scour protection systems for a gravity based foundation for offshore wind turbines (Kolkbildung und Dimensionierung des Kolkschutzes eines OWEA Schwerkraftfundaments), HTG-Kongress 2011, 07.-10.09.2011, Würzburg, published in: Proceedings of the HTG-Kongress 2011, Editor: German Port Technology Association, Hamburg (in german)

PMCid:3041714

Zanke, U.C.E., Hsu, T.-W., Roland, A., Link, O., Diab, R. 2011. Equilibrium scour depths around piles in noncohesive sediments under currents and waves, Coastal Engineering, 58, 986-991.http://dx.doi.org/10.1016/j.coastaleng.2011.05.011


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