1,300-tonne viaduct deck slid into place on HS2 route

Yahoo

14 hours ago

A 1,300-tonne viaduct deck has been slid into place as part of HS2.
The viaduct, which is 220 metres long and constructed from steel and concrete, was assembled alongside its final location before being carefully moved into position over three days, reaching its northern abutment on June 20.
Sam Arrowsmith, project manager at HS2 Ltd, said: "It's great to see the viaduct deck in position and I'd like to thank everyone who's helped get us to where we are today.
"The slide may only have taken three days, but it was the culmination of four years of work – developing the design, completing the groundworks and the piers and assembling the enormous steelwork."
The viaduct will eventually carry high-speed trains over Banbury Lane and forms part of the new HS2 route between London and the West Midlands.
It is designed to manage flood risk by maintaining natural water flow in the valley, and features weathering steel intended to blend into the rural landscape.
The deck was slid into place using PTFE-coated pads to reduce friction between the structure and the temporary steel bearings on the five supporting concrete piers.
Lower Thorpe is the last of five viaducts installed using this method by EKFB, the main contractor for the central section of HS2.
EKFB is a consortium comprising Eiffage, Kier, Ferrovial Construction and BAM Nuttall.
With the steelwork now in place, the next phase will see the deck lowered 60 centimetres onto its permanent bearings, followed by construction of the concrete deck and parapets.
Janice McKenna, technical director at EKFB, said: "The strategic design approach applied to these double composite structures has been a game-changer in how we're building these viaducts.
"The double composite solution can be applied to multiple structures in different locations, and we have five across EKFB's 50-mile route that are all well into construction.
"The philosophy was to design the viaducts with architectural input to 'blend' the structures into their respective landscapes and reduce the visual impact on the environment.
"We also required a solution that offered specific delivery benefits too, from saving embedded carbon in the materials we use, to enhancing productivity on site and reducing safety risk."
The double composite design uses steel beams with reinforced concrete layers above and below, reducing the carbon footprint by up to 59 per cent compared to traditional pre-stressed concrete beams.
The viaduct will eventually support high-speed trains between London and the West Midlands, easing congestion and increasing capacity on the existing rail network.