Final section of Al Wasl dome lifted into place at Expo 2020

The final piece of Al Wasl dome has been fitted into place following an intricate and complex construction operation at the Expo 2020 Dubai site.
Enclosing a space of 724,000 cubic metres and standing 67.5 metres tall - higher than the Leaning Tower of Pisa - the 130-metre-wide domed steel trellis encircles Al Wasl Plaza, a structure that will be the heart of the Expo 2020 site and set to become Dubai's latest architectural landmark. During Expo 2020, Al Wasl dome will be the largest 360-degree projection surface in the world, providing an unparalleled experience for millions of visitors.
Sheikh Ahmed Bin Saeed Al Maktoum, chairman of the Expo Dubai 2020 Higher Committee, president, Dubai Civil Aviation Authority, chairman, Dubai Airports, and chairman and chief executive, Emirates Airline and Group, said: "The crowning of the Al Wasl dome is a significant landmark not just for Expo 2020 Dubai, but for the whole of Dubai and the UAE. This new architectural marvel joins a long list of inspiring designs that our country has created through collaboration, sheer hard work and the unending, ambitious vision of our leadership and people. It is another example of what the nation can do when it combines all its talents to such formidable purpose. Al Wasl dome will take a lasting place at the very summit of our country's world-renowned architectural achievements. My heartfelt congratulations go to everyone involved in successfully completing this amazing engineering feat."
The highly intricate operation, involving hundreds of on-site technicians who used special lifting equipment, was a unique engineering challenge, according to Ahmed Al Khatib, chief development and delivery officer, Expo 2020 Dubai. "It was the most exhilarating day of my entire career. We had one chance to get this right. Lifting such a large and heavy structure involved a huge number of variables. Something as simple as a shift in direction of the wind or change in air temperature could have had a big impact on our calculations, so constant monitoring and reassessment was essential throughout the process."
Weighing 550 tonnes of moulded steel, Al Wasl dome's 22.5-metre crown had to be precisely positioned on top of the vertical trellis, with a margin of error of only three millimetres. It was completed using a technique called strand-jacking. Including the structures and equipment required to lift the dome during this process, the total weight was 830 tonnes - equivalent to 600 saloon cars. Eighteen hydraulic jacks, aided by steel lifting ropes connected to 18 freestanding temporary columns, were used to slowly raise the curved steel crown. It was positioned directly on top of the trellis already in place 45 metres above the ground, and attached using 53 temporary connection brackets. Working through the night, 800 engineers and construction technicians carefully monitored every millimetre of the process, using GPS indicators throughout to ensure perfect alignment.
Al Wasl dome's crowning was the culmination of 14 months of preparation, beginning when the final pieces of the dome's steel trellising left Italy on June 26, 2018. The individual elements first arrived in Dubai in July 2018 and the crown was carefully assembled at ground level before being raised into place. Now positioned, the final piece of Al Wasl dome will be welded to the rest of the trellis, a process that will take 25 days to complete.
- rohma@khaleejtimes.com