A new piling technology, known as hollow impressed precast energy reusable pile (HIPER), is being trialled at HS2’s Euston station site.
The environmentally-friendly solution takes advantage of a new technique that swaps solid concrete foundation piles for recyclable hollow ones made from steel industry waste.
This reduces the carbon-intensive cement content by up to 70 percent.
Developed by civil engineers from Keltbray as part of HS2’s innovation programme, HIPER will be tested by HS2 contractors Mace Dragados at the London site.
The hollow tube piles will draw ground heat up through the foundations of a newly built construction site office and it’s estimated that they could harness enough energy to supply 80 percent of the building’s heating and hot water.
As part of the site office’s foundations, the piles will be bored up to 25 metres into the ground and filled with water, before pipes carrying cold flowing water to and from the building are run through each pile cylinder.
As the ground’s heat warms the standing water in the cylinders, this heat is transferred to the pipes and carried to the surface to supply the building’s heating system and hot water.
The technology can also be reversed in the summer, cooling the building by transferring heat back into the ground.
HS2 engineers are already exploring how HIPER could be used to supply zero carbon renewable energy to the project’s Euston and Curzon Street stations.
“The innovation combines a number of novel technological breakthroughs to deliver the first major change in the piling industry for over 70 years.
“HIPER piles use zero-cement concrete, halving embedded carbon emissions compared with traditional methods.
“The fact that HIPER piles are hollow also means that they are 60% more thermally conductive so they can harness the earth’s natural zero-carbon thermal energy more efficiently than conventional solid thermal piles.”
