HS2 designers are set to more than halve the amount of embedded carbon used in one of the high-speed rail project’s viaducts.
Wendover Dean Viaduct cutaway image showing double composite structure
A double composite approach will be used on the Wendover Dean Viaduct in Buckinghamshire. This involves two steel girders sandwiched between two layers of reinforced concrete to create a super strong but lightweight span.
The 450m viaduct was recently given approval by Buckinghamshire Council under Schedule 17 of the HS2 Act and will be the first major railway viaduct in the UK to use this design approach.
it is one of 50 being built on the first phase of HS2 between London and the West Midlands, and has been designed by HS2’s main works contractor, EKFB – a team made up of Eiffage, Kier, Ferrovial and BAM Nuttall – working with design partner ASC (a joint venture between Arcadis Setec and COWI) and specialist architects Moxon.
Applying lessons from the use of double composite structures on the latest French TGV lines, the designers have cut the amount of embedded carbon in the viaduct by 7,433 tonnes – the equivalent of 20,500 return flights from London to Edinburgh.
In addition to reducing the amount of concrete and steel used in the structure – both significant sources of carbon dioxide – the slim design also decreases the structure’s silhouette when seen from across the valley. Nine equidistant piers will hold up the deck of the viaduct.