HS2 Ltd has unveiled the final designs for the Thame Valley Viaduct.
The 880-metre long structure will be made from prefabricated concrete segments that will simply slot together like LEGO bricks.
The viaduct will cross the flood plain of the River Thame (a tributary of the Thames), just outside Aylesbury, carrying high-speed HS2 trains.
Set low into the landscape, the underside of the viaduct will be just three metres above the ground, with 36 spans, each 25-metres long.
The 35 concrete piers that support the viaduct will also be entirely made offsite before being placed on their foundations.
Expected benefits of this approach include improved durability and reliability, saved time, cost savings and improved safety by reducing the need for people to work at height.
Thame Valley is one of 15 viaducts to be built by EKFB – a contracting consortium of Eiffage, Kier, Ferrovial Construction, and Bam Nuttall – working with design partner ASC (a joint venture between Arcadis, Setec, and Cowi) and specialist architect Moxon.
Tomas Garcia, HS2 Ltd head of civil structures, said: “Prefabrication and off site manufacturing offer huge benefits in terms of efficiency and this design will help us deliver a more efficient, durable and elegant structure with less concrete and steel.”
Janice McKenna, EKFB technical director, added: “The structurally efficient solution means we minimise the embedded carbon in the viaduct materials; and we have also been able to reduce emissions during construction by maximising off-site pre-fabrication to achieve an efficient build, as well as reducing the number of HGVs on local roads.”
Preparatory works have already begun on site near Aylesbury, with the design team also looking at whether a similar modular approach to construction can be applied to other, smaller viaducts elsewhere on the route.
Main image: A render of the new viaduct (Credit: Moxon)
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