Saskia Pfoertner, Hocine Oumeraci, Matthias Kudella, Andreas Kortenhaus


The Ocean Brick System (OBS) is a modular system consisting of hollow concrete precast blocs (10m x 10m x 10m) piled up like cubes and interconnected to create a stiff, light and strong structure which can be used for artificial islands, artificial reefs, elevation of vulnerable low lands, deep water ports, breakwaters and foundation of offshore wind turbines. The paper focuses on the experimental results on the wave loading and the stability of the OBS used as
a foundation of the support structure of offshore wind turbines. Diagrams for the prediction of total horizontal forces, vertical forces and overturning moments induced by irregular waves on the OB-structure are derived and verified through additional stability tests and stability analysis.


modular structure; offshore wind turbine; total wave loads; sliding/overturning stability; rubble foundation

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Bos, K.J.; Verheij, H.J.; Kant, G. and A.C.H. Kruisbrink. 2002. Scour protection around gravity based structures using small size Rock. First International Conference on Scour of Foundations, Texas University, College Station, Texas, USA, pp. 567-581.

CIRIA/CUR/CETMEF. 2007. The Rock Manual. The use of rock in hydraulic engineering. CIRIA / CUR, CIRIA C683, 2nd edition, London, 1236 p.

DenBoon, J.H.; Sutherland, J.; Whitehouse, R.J.S.; Soulsby, R.; Stam, C.J.; Verhoeven, K.; Hoegedal, M. and T. Hald, T. 2004. Scour behaviour and scour protection for monopile foundations of offshore wind turbines. Proc. EWEC.

Jensen, O.J. and P. Klinting. 1983. Evaluation of scale effects in hydraulic models by analysis of laminar and turbulent flows. Amsterdam, The Netherlands: Elsevier, Coastal Engineering, vol. 7, pp. 319-329.http://dx.doi.org/10.1016/0378-3839(83)90002-9

Madrigal, B.G. and J.M. Vald├ęs. 1995. Study of rubble mound foundation stability. Proceedings Final Project Workshop, MAST II, MCS-Project: Monolithic (Vertical) Coastal Structures, Alderney, U.K., 38 p.

O'Loughlin, E.M.; Mehrotra, S.C.; Chang, C. and J.F. Kennedy. 1970. Scale effects in hydraulic model tests of rock protected structures. IHHR Report No. 24, Iowa University, 37p.

Oumeraci, H. (2009). Non-conventional wave damping structures. Handbook of Coastal and Ocean Engineering. P. Y. C. Kim. USA, World Scientific Publishing: 34 p., in print.

Oumeraci, H.; Pfoertner, S.; Kudella, M. and A. Kortenhaus. 2008. Ocean Brick System (OBS) in a Wave Flume - Part I: A Foundation Structure for Offshore Wind Turbine. LWI Report No. 972, Leichtweiss-Institute, pp. 73 + 3 annexes.

Tanimoto, K.; Yaghu, T. and Y. Goda. 1982. Irregular wave tests for composite breakwater foundation. Proceedings 18th International Conference Coastal Engineering (ICCE), ASCE, Volume 3, Capetown, South Africa, pp. 2144-2163.

USACE. 2002. Coastal Engineering Manual. Engineer Manual 1110-2-1100, US Army Corps of Engineers, Washington D.C., USA (in 6 volumes).

Vos, L.D.; De Rouck, J. and P. Troch. 2006. Design of scour protection around offshore monopiles under combined wave and current loading. Pro. OWEMES.

DOI: https://doi.org/10.9753/icce.v32.structures.66