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Webinar: Morphological Desk Study Hollandse Kust (west)

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    06-11-2020 13:00:00 06-11-2020 14:30:00 Europe/Amsterdam Webinar: Morphological Desk Study Hollandse Kust (west)   Introduction: Tom Roetert and Hendrik Jan Riezebos (Deltares) will guide you through the assessment of the seabed dynamics and scour mitigation strategies at the HKWWFZ. The study is based on existing historical bathymetrical data and the survey results obtained in the geophysical campaign. A panel of the following experts: Tom Roetert, Hendrik Jan Riezebos (Deltares), Ben de Sonneville (BLIX Consultancy) and Behzad Aziz (Netherlands Enterprise Agency, RVO) will be present to answer... noreply DD-MM-YYYY
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By Dia de Wijs 40 days ago
06-11-2020 13:00
06-11-2020 14:30

 

Introduction:

Tom Roetert and Hendrik Jan Riezebos (Deltares) will guide you through the assessment of the seabed dynamics and scour mitigation strategies at the HKWWFZ. The study is based on existing historical bathymetrical data and the survey results obtained in the geophysical campaign.

A panel of the following experts: Tom Roetert, Hendrik Jan Riezebos (Deltares), Ben de Sonneville (BLIX Consultancy) and Behzad Aziz (Netherlands Enterprise Agency, RVO) will be present to answer any questions on the morphodynamics and scour mitigation.

Supplier: Research institute Deltares

Results of this study:

The bathymetry in the HKWWFZ has a non-uniform morphology including two prominent sand banks and a full coverage of sand waves with megaripples on top. The sand waves are migrating towards the north-northeast with locally some minor variations caused by the presence of the sand banks. Considering the entire HKWWFZ, the sand waves have typical wavelengths in the range of 160 to 540 m, heights of 0.7 to 4.8 m and typical migration speeds up to 4.1 m/year with a median speed of 2.3 m/year. An analysis of the large-scale seabed variations shows the underlying seabed may be considered static over the lifetime of the wind farm. To support the data-driven analysis a sediment transport was applied to the area indicating similar spatial patterns of sediment transport. For a more detailed geological understanding of the sand waves, for a total of ten sand waves, five vibrocores per sand wave were investigated.

To decide which strategy for scour mitigation can best be adopted for a certain foundation type and specific location, information was presented on how to predict the scour depth (when not protected) and how to protect against scour, taking into account the morphodynamic scenarios of stable, lowering, and rising seabeds.

It can be concluded that for monopiles an easy-applicable, well-proven solution is to place the monopiles 1) in areas with limited seabed dynamics; 2) just north-east of the sand wave crests; or 3) on top of the sand wave crests and to apply a scour protection to maintain a more or less fixed seabed level around the foundation. In the second case, a slightly longer pile is needed, while, in the third case, a longer or thicker scour protection is recommended to cater for the lowering seabed.

The deliverables of this assessment: The results of the morphodynamical assessment are available at: https://offshorewind.rvo.nl/soilw

Preparations webinar: Please take notice of the morphodynamical deliveries prior to the webinar, in order to be prepared to ask questions. The webinar will be held on an anonymous internet platform, so your questions will not be traceable to you or your company.

Registration: Please register via woz@rvo.nl, stating your name, company, email address and subject of the webinar of your choice. Latest one day prior to the webinar you will receive a weblink.