SPT Offshore has launched a new wind turbine suction pile foundation concept, which combines mono tubulars with suction pile foundations. The company is now detailing the design and working towards a demonstration in the next 12 months.
The concept involves a star shaped transition piece that is positioned in between the three (or potentially four) suction piles and the mono tubular.
SPT Offshore highlighted that the concept leads to cost savings. The company said that the mono tubular has is inexpensive to fabricate, being some 3 times less expensive than jackets. Furthermore, the suction piles have several advantages, including fast and noise-free installation. Also, suction piles do not cause any shocks to the foundation, so that single piece installation up to the work platform is possible, SPT Offshore said.
The company went on to say that suction piles are significantly optimised if smaller outer diameters are being selected compared to the depth, reducing weight and improving reliability and strength.
The suction piles should be placed horizontally further apart to be more effective, SPT said, so the load transfer from the mono tubular to the suction piles requires a transition piece, which can be built out of steel or concrete.
On top of the suction piles and on top, or possibly inside, the transition piece there is room for added ballast, which can be pre-installed or combined with rock scour protection measures after installation.
SPT Offshore said that suction piles are suited for 99% of the North Sea and most shallow water areas worldwide having sandy, clayey or layered soils.