SUB-SEABED BOULDERS LOCATED AT WIND FARM SITE: Prior to driving piles into the sub-seabed floor to serve as foundations for wind turbines, it is critical to ensure that the chosen locations are free from boulders and geohazards. A boulder of a half-metre or greater is enough to stop a piling operation. If the pile strikes a boulder in the zone halfway down, it may be difficult to either retrieve the pile or drive it farther into the seabed. Avoiding this is important due to the cost of the pile (approximately USD2 million), the time it takes to replace it, and the need to ensure it does not pose a hazard to navigation.
At a wind farm site on the Baltic Sea, previous site investigations and tunnel excavation historical records indicated that the seafloor was strewn with boulders and the stratigraphy was complex. The wind farm operator’s concern was that boulders existed in equal concentrations under the sea bed.
PanGeo Subsea was contracted to survey 25 potential turbine foundation sites using the Acoustic Corer (Corer) to identify and locate boulders and geohazards… CLICK HERE to read the full story as presented in the September Issue of Hydro International.