In a double milestone for engineers, HS2 has marked the next stage of two new viaducts near the town of Brackley, bringing the high-speed railway one step closer to reality.
The work has seen the construction of a 2,695-tonne deck slide for the Westbury viaduct as well as the completion of the abutments at either end of the nearby Turweston viaduct.
Crossing the floodplain of the River Great Ouse, the twin structures use an unusual ‘double composite’ approach, with layers of reinforced concrete above and below the steel beam, in turn creating an efficient box-beam – this uses less carbon-intensive concrete and steel than more traditional designs.
The viaducts
The structure in Westbury stretches for 320 metres and was finished in three stages as part of a project that took six months to complete. Engineers will now begin the work of lowering the deck 60 centimetres onto the permanent bearings to support the weight of the structure. This will take two months to complete.
Engineers at Turweston, on the other hand, will now turn their attention to assembling the deck girders for launch of the 591-tonne structure next year. The work at both viaducts is being conducted by HS2’s main works contractor, EFKB, which is made up of:
- Eiffage
- Kier
- Ferrovial Construction
- BAM Nuttall
Huge potential
“It’s been incredible to watch the enormous deck at Westbury come together over the last year and see it so carefully slid into position,” said HS2’s senior project manager, Elizabeth Longinotti.
She added: “I’d like to thank everyone who helped make it happen – and I look forward to seeing similar progress at Turweston in the coming months.
“The innovative double composite structure they share has huge potential to cut carbon in construction by enabling more efficient bridges and I hope that the lessons we have learnt can be successfully applied to other projects across the UK in the future.”
Image credit: HS2
