ALTRAD RMD Kwikform has provided details of its work to supply a large-scale bespoke temporary works solution to Balfour Beatty VINCI Joint Venture to support the construction of the new ‘Curzon No. 3 Viaduct’, as part of the HS2 Curzon Street Railway Station in Birmingham.
The formwork and falsework has been assisting with the build of four viaduct decks, which will be coming out of the station and merging into one single bridge deck featuring three high-speed tracks.
Altrad RMDK explained the falsework configuration needed to be designed in a particular way to allow the transfer of the loads from the concrete deck and wind forces down into the foundations without overloading the structure, ensuring it could support itself at all stages of erection, in-situ concrete pouring and dismantling. The firm’s engineers also made the provision to ensure that after the pour of concrete, the site team could easily and safely move the falsework and formwork deck units to be re-used elsewhere on site.
Several interconnected products were specified, combining the Rapidshor falsework system with Alform aluminium beams and Superslim Soldier formwork beams to create the formwork cradles. Slimshor propping with clear span steel beams and further Alform decking beams were used to support the deck soffit over the V-shaped void in the piers, with Megashor wailings to stabilise the side shutters.
A fully braced falsework system was the chosen method of support, with supports at 1.2-metre centres down the length of the viaduct. A fully braced method was required so the structure would not move in any direction and was entirely restrained by its internal bracing. Altrad RMDK revealed it achieved the deck profile with a system of aluminium wailings and Superslim primary beams, which sat on the top of the falsework and incorporated a cantilevered support to the wings of the deck.
Due to the tight radius curves on the underside of the decks, a special formwork solution was designed to ensure the desired form and finish was met. Altrad RMDK worked with Cordek to achieve the right shape and finish, devising a complete solution for the rounded corners.
To minimise the dangers that arise when working at height, the falsework solution was designed so it could largely be constructed horizontally and connected before being craned into a vertical position.
Sustainability on the project was boosted by the fact the whole temporary works structure was designed in a way that it could be lifted away and then used elsewhere.
Cliff Shepherd, senior project engineer at Altrad RMDK, said, “This has been one of the largest projects that I have worked on in my career of over 33 years, and the entire Altrad RMDK team are extremely proud to be a part of this historic scheme. This is a brilliant example showcasing not only Altrad RMD Kwikform’s engineering excellence, but also demonstrates how inter-compatible and versatile our equipment is when working together to form very complex shapes.”
Lenka Vošvrdová, senior agent at Balfour Beatty VINCI’s Curzon Street site, added, “We recently completed the first sections of our Curzon 3 Viaduct – a significant moment for everyone connected with this iconic structure in the middle of Birmingham city centre. This achievement was only possible thanks to the hard work, skill and expertise demonstrated on a daily basis by the Balfour Beatty VINCI site team and our supply chain partners.”
