Pore Pressure Under A Gravity Based Structure Under The Influence Of Waves

The total wave load on a gravity based foundation for offshore wind turbines is influenced by the pore pressure from beneath the structure. The pore pressure is induced by the wave–structure-seabed interaction. Often the uplift force is included in a simplified way in the design of the gravity based...

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Bibliographic Details
Published in:Volume 10: Ocean Renewable Energy
Main Authors: Christensen, Erik Damgaard, Carstensen, Stefan, Madsen, Mikael Thyge, Allerød Hesselbjerg, Peter, Nielsen, Christel Jeanty
Format: Article in Journal/Newspaper
Language:English
Published: American Society of Mechanical Engineers 2017
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Online Access:https://orbit.dtu.dk/en/publications/659adf48-6879-434d-950d-64a59ffe427f
https://doi.org/10.1115/OMAE2017-62585
Description
Summary:The total wave load on a gravity based foundation for offshore wind turbines is influenced by the pore pressure from beneath the structure. The pore pressure is induced by the wave–structure-seabed interaction. Often the uplift force is included in a simplified way in the design of the gravity based foundation. This leads typically to very conservative designs in order to accommodate the uncertainties in the procedure. The experiments shall lead to better prediction models based on for instance CFD model’s with the direct calculation of pressure variations in the seabed and any erosion protection layer. Herewith, it will be possible to get a direct assessment of wave loads on the foundation, also under the seabed level. The study includes experiments as well as numerical analyses. A good agreement between the experimental results and the numerical analyses was found. In the numerical analyses, it was possible to investigate the effect of air content in the pores, which turned out to have an effect on the distribution of the pore pressure.