HS2 has started erecting a major rail viaduct which has been manufactured off-site, in what it said was a first for the UK.
All major elements of the 880-metre-long Thame Valley Viaduct near Aylesbury are being taken off-site before being “assembled on site like a giant Lego set”, HS2 Ltd said .
The public corporation said the modular approach will reduce the carbon footprint of the structure by about a third.
The 68 concrete piers for the viaduct are being cast at the Kent factory of the British subsidiary of the Spanish company Pacadar, before being transported to the site by road. The first 14 piers were put into position over the past four weeks.
Each span of the viaduct will include two prefabricated hollow beams 25 meters long. HS2 said this approach “reduces the amount of carbon-intensive concrete and steel, while simplifying work on site”.
HS2’s Head of Civil Structures, Tomàs García, said the viaduct represented “a huge step forward in terms of structural design”.
He said off-site manufacturing would be “dramatically [improve] efficiency, safety and quality while delivering exceptional performance and durability.”
Garcia said structures similar to the viaduct “will also help us develop new ways to reduce carbon embedded in construction that can be adopted across the rest of the industry in the future.”
Last month, Pacadar’s UK production manager said the viaduct was based on a modular design “which is widely implemented by Pacadar on previous high-speed lines”.
The viaduct was designed by HS2’s main works contractor, EKFB, a joint venture of Eiffage, Kier, Ferrovial Construction and Bam Nuttall. They worked with specialist construction partner FC Civils Solutions.
FC Civils head of operations, Tiago Palas, said work is underway on other elements of the site, such as the construction of pile caps and the production of beams ready to be installed in autumn..
He said putting the piers in place was “a relatively quick process, an efficiency made possible by their innovative design and construction methodology.”
The HS2 project is running substantially over budget, with the government recently admitting that the planned Euston station was “unaffordable” at its current estimated cost.
