Numerical estimation of ORE export cables burial depth in a marine dune environment : the Dunkirk offshore wind farm study case

1. Home
2. Publications
3. Online Library
4. Numerical estimation of ORE export cables burial depth in a marine dune environment : the Dunkirk offshore wind farm study case

Many Offshore Renewable Energy sites (offshore wind turbine farms and export cables) are constructed or planned in areas of high sediment mobility. Over such mobile sediment, it is frequent that large marine dunes (several meters high) develop and migrate (sometimes several meters per year). In presence of sandy substrates, submarine cables are generally buried at a depth of at least 1 meter below the (minimum) seabed level in order to ensure a sufficient protection. In case marine dunes migrate over the cable, bathymetric variations might reach several meters and cables might get over buried or exposed. Designing an adequate initial cable burial depth in such a dynamic environment is therefore particularly challenging. Here, we use a morphodynamic numerical model to assess the bathymetric variations over a planned cable route in an area of large active marine dunes. It focuses on an area located along the two export cables routes of the planned Dunkirk offshore wind farm (France), where multiple dunes ranging from 0.8 to 2.1 meters high and migrating up to 28.5 m per year are present. A configuration considering a morphological acceleration factor of 20 is setup over 4 months. A validity period is defined using multiple bathymetric surveys carried out prior to the cable installation. Using the maximum range of this period, the depth variations are studied along each cable route to provide estimations of both an appropriate burial depth and information for the cable design.

5th International Symposium on Frontiers in Offshore Geotechnics (ISFOG2025)

15 - Mooring lines, Cables, Pipelines, Immersed tunnels and Risers