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Webinar Morphodynamics and Scour Protection TNW

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    17-02-2022 10:00:00 17-02-2022 12:00:00 Europe/Amsterdam Webinar Morphodynamics and Scour Protection TNW Introduction: Tom Roetert and Antonios Emmanouil (Deltares) will guide you through the assessment of the seabed dynamics and scour mitigation strategies at the Ten Noorden van de Waddeneilanden Wind Farm Zone (TNWWFZ). 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, Antonios Emmanouil (Deltares), Matthew Wright and Kevin Black (both Partrac) and Diederik van Hogendorp... noreply DD-MM-YYYY
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By Dia de Wijs 28 days ago
17-02-2022 10:00
17-02-2022 12:00

Introduction:

Tom Roetert and Antonios Emmanouil (Deltares) will guide you through the assessment of the seabed dynamics and scour mitigation strategies at the Ten Noorden van de Waddeneilanden Wind Farm Zone (TNWWFZ). 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, Antonios Emmanouil (Deltares), Matthew Wright and Kevin Black (both Partrac) and Diederik van Hogendorp (Arcadis) 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 TNWWFZ is considered to be relatively static because of the limited presence of bedforms and seabed dynamics. The top sediment layer is partly mobile and covered with a few bedforms oriented towards the east with some small megaripples on top. When taking into account uncertainties, the bedforms are typically migrating towards the east with migration rates between -0.1 (towards the west) and +0.6 m/year. Considering the entire TNWWFZ, the bedforms have typical lengths in the range of 710 to 1170 m and heights in the range of 0.4 to 0.8 m. 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 morphodynamics in the area a number of boreholes and Vibrocores 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 in areas with limited seabed dynamics such as TNW and to apply a scour protection to maintain a more or less fixed seabed level around the foundation. Other solutions are also possible, such as leaving out the scour protection completely at locations where scour protection costs outweigh the costs for additional steel consumption.

Lastly, general considerations for cable routing in a morphodynamic area such as TNW are discussed. It is expected that cables can be buried sufficiently deep to avoid cable exposure, when smart cable routing techniques are adopted, which avoid the areas with largest morphodynamic seabed lowering or other “expensive” areas with higher risks.

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

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 to participate anonymously in the webinar.