Just outside Kuwait City, the Jaber Al-Ahmed International Stadium is under construction on 400,000m 2 of desert.
The Gulf region's timber-built merchant ships gave architect Weidleplan Consulting the inspiration for the 250m diameter stadium that curves up at either end, echoing the shape of a traditional dhow.
The design calls for the construction of 52 main structural walls rising as high as 65m to form the support for the seating terraces. These have cantilevered beams protruding from their upper corners to support the upper tiers of seats.
The cantilevered beams provided a particular challenge for the contractor joint venture of Mohammed Abdulmohsin, AlKhara & Sons, WLL and Philipp Holzmann, which is due to nish the project in December.
It had to come up with a way of supporting the beams without using expensive falsework, and eventually decided on a solution developed by Austrian formwork specialist Doka.
The wall bases are being cast using eight complete formwork sets made up of large area formwork and climbing brackets. These allow a crane to hoist up the formwork as the pier is cast, says Doka spokesman Heinrich Ecker.
For the inclined sections, which extend as far as 50m from the top of the walls, a cantilever jump formwork system has been developed.
This permits huge equipment and labour savings by eradicating the need for falsework, Ecker claims.
Sustaining its own dead weight, wind loads and the weight of the fresh pour, the formwork transfers the loads of freshly poured concrete to previously cured sections.
On the underside of the cantilever the formwork is supported off two steel girders attached by two climbing shoes. On the upper side, the whole system is back-stayed with two 10m long tie rods with a failure load of 100t.
After each pour, the system is held in place by a crane while the tie rods are detached from the back stays. The crane then hoists the 14t formwork unit up and along to the next section, where it engages with previously mounted suspension shoes, adds Ecker.