With the first offshore windfarms nearing the end of their operational life, solutions for efficient pile removal are set to become pivotal to the piling industry within the next five to ten years. IQIP is working on an innovative solution to allow for complete pile removal and, where that is not possible, a safer and more efficient partial removal.
As wind energy on- and offshore continues to grow so does the number of piles driven into the ground and seabed all over the world. However, with a typical pile lifespan of 20-25 years, the next decade will see an increasing need not just for more pile installations but for efficient, safe, and environmentally responsible pile decommissioning. Currently, environmental conditions require the removal of all foundations above ground and several meters below seabed level. This can be challenging, especially underwater, as current removal techniques consist of dredging and cutting the piles; something which only gets more complicated as piles grow and reach deeper depths.
However, with the new method being developed by IQIP, the health and safety risks to the divers currently carrying out the underwater cutting can be avoided. Furthermore, with more steel to sell as scrap, costs can be reduced. Joop van Dijk, product manager, explains. “To remove an installed hollow pile (tube), we can use the well-known technique of closing the pile at the topside, filling the pile with a medium, liquid, and by pressurising the liquid, the pile will raise out of the soil by the built-up pressure.” However, there are a number of challenges in the realisation of this method including the possibility of the liquid medium leaking into the soil and preventing the needed pressure from being created. This is one of several challenges, IQIP is currently solving with new methods and technologies.