Thame Valley viaduct for HS2 project will be fully manufactured offsite

The Thame Valley viaduct, which will carry the High Speed 2 (HS2) railway, will be the first on the giant infrastructure project to be fully manufactured offsite, which is set to reduce the carbon footprint of its construction.

All significant components of the viaduct, which spans 880 metres, which include 97-tonne beams and 42-tonne supporting piers are in production at concrete structures group PACADAR UK’s factory in Kent.
Engineers said this will result in a carbon footprint reduction of around one-third.

"HS2 will offer zero carbon journeys from day one, providing a cleaner, greener way to travel and help the fight against climate change. But we’re also serious about cutting embedded carbon in construction, reducing cost and programme and improving safety, performance and durability," said Tomas Garcia, HS2’s head of civil structures.

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"Thames Valley is a great example of how our contractors are embracing the latest engineering techniques to do just that. It’s great to see the start of work at PACADAR UK, and I look forward to seeing assembly begin on-site later this year."

HS2’s main contractor EKFB, are working with FC Civils Solutions and PACADAR UK to design and construct the Thame Valley viaduct as part of an HS2 initiative that includes 15 viaducts.

Conventionally, viaduct beams are joined using a cast-in-situ concrete diaphragm above each pier but Thame Valley will use large pre-cast beams that can be directly secured to each other. This method eliminates the need for a diaphragm, resulting in better durability, reliability, time savings, cost reductions, and improved safety.

All 68 concrete piers supporting the viaduct will be fully prefabricated off-site and then installed on their foundations.

"This internationally inspired design is the product of best-in-class collaboration between HS2, EKFB and its design partners, Ferrovial Construction and FC Civils Solutions. The solution is a lightweight viaduct, set low into the landscape, that benefits from the efficiencies associated with off-site prefabrication," said EKFB project director Ignacio Chicharro.

The viaduct will carry the high-speed HS2 train at speeds of up to 360km/h, connecting London, Birmingham, and the north. It is also set to create additional capacity for freight and local services on the current network.