Gravity Based Foundations
The Gravity Based Foundation is a concrete conical / cylindrical structure of some 45m in height. This massive structure was built onshore, at the “Halve Maan” site in Ostend, and transported semi-submerged to the offshore site, where it was put on the seabed. An “empty” GBF weighs some 3000 tons. Once installed on the seabed, it was filled with sand; its total mass is 6000 tons.
|GBF height||38,5 m to 45 m|
|GBF weight||2800 tonnes to 3000 tonnes|
|Material||+/- 1060 m3 concrete + 255 tonnes reinforcement|
|Diameter base slab||23,5 m|
|Thickness concrete wall||0,5 m|
The jacket foundation is a steel quatropod structure grouted to and supported by 4 pin piles. The pin piles (+-2 m in diameter) are up to 50 m long and driven into the seabed. A transition piece is welded on top of the jacket, providing an access platform with 2 cranes and a cylindrical “barrel” to support the tower of the turbines.
|Jacket height||37,7 m - 47,8 m|
|Jacket weight||+/- 500 tonnes|
|Jacket OTS weight||800 tonnes|