Mobile bedforms such as sand banks and sand waves cause several challenges when designing and constructing an offshore windfarm. These include: defining design seabed levels prior to installation; incorporating the potential for morphological change into foundation and scour protection design; cable installation; and the choice of installation tools.
Over a period of several years, Ørsted commissioned us to undertake a series of investigations into seabed mobility at their Race Bank wind farm site, located on a highly complex and dynamic area of seabed in the Greater Wash.
Using a combination of project specific geophysical and geotechnical data, historic seabed charting and metocean data, we mapped the behavioural characteristics of the seabed. This was carried out across both the wind farm site and export cable corridor.
Numerical computing software was subsequently used to provide quantitative assessments of potential future bed level change above/below a design level for multiple target locations throughout the project lifetime. This information was used to help inform aspects of project design including optimal cable burial depth.
The wind farm was officially opened in 2018 and is now fully operational.