Al Wasl dome for Dubai Expo 2020 is an architectural marvel

In 1851, the Crystal Palace was the centrepiece of London’s Great Exhibition – the first World Expo. It celebrated the man-made industrial wonders of a rapidly changing world. Architecture, contents, and the theme ‘Industry of All Nations’ came together to create a big idea of nations meeting nations in shared technological and commercial progress.

And now, decades later, Expo 2020 Dubai - the first Expo to be held in the Middle East, Africa and South Asia - intends to bring together millions of people celebrating human brilliance and achievement under the theme 'Connecting Minds, Creating the Future'. The Expo will take place for six months - from October 20, 2020-April 10, 2021. With 25 million people expected, and 70 per cent from outside the UAE, Expo 2020 aims to entertain guests with 60 daily events across 173 days. The visitors will have access to the latest innovations and breakthroughs, with more than 200 participants – including 192 nations, multilateral organisations, businesses and educational institutions – joining hands to highlight real-life solutions to the world’s most pressing challenges.

The Expo will host hundreds of pavilions, also including the sub-themes 'Opportunity, Mobility and Sustainability'. Three pavilions are dedicated to each of the sub-theme, while 37 pavilions belong to particular countries including China, Morocco, UK and Canada among others. The pavilions are being designed by renowned architecture firms - WOHA is designing the Singapore Pavilion, the Mobility Pavilion is being designed by Foster + Partners, the UAE Pavilion by Santiago Calatrava, the Sustainability Pavilion by Grimshaw architects, and the USA Pavilion by Fentress Architects. However, what is expected to gain maximum attraction is the Al Wasl Plaza, for it will act as the centrepiece for the extravaganza.

The central pavilion - Al Wasl Plaza

The name Al Wasl means ‘connection’ in Arabic, and hence, Al Wasl Plaza has been designed to work as the central core of the entire Expo 2020 site, connecting the three Thematic Districts, and providing a focal point for visitors throughout the six-month event. The Plaza has been designed to form a grand ‘urban room’, a meeting place that creates a shaded microclimate unlike anywhere else in Dubai. After the completion of Expo 2020, the Al Wasl Plaza will remain a central point of District 2020, an interconnected, multi-purpose development capable of hosting a range of different events, from intimate occasions to large-scale functions with crowds of up to 10,000.

The plaza, which is topped by a unique and iconic dome, has been designed by US-based firm, Adrian Smith + Gordon Gill Architecture. The raw steel for the trellis was sourced from the Czech Republic, Hungary and Poland, and the steel was shaped into its flowing curves by companies from Belgium, Germany and Spain before being moulded into its intricate latticing in Italy by Cimolai Rimond.

The crown: Al Wasl dome

The intricate trellis of the Al Wasl dome, which encloses the Al Wasl Plaza, is a 3D visualisation of the Expo 2020 logo and comprises 13.6 kilometres of steel. It was originally divided into 1,162 individual sections that were then welded together into 600 elements in factories in Italy and Abu Dhabi. At 130 metres wide and 67.5 metres tall, the dome weighs a total of 2,544 tonnes –  as much as 25 blue whales.

The Al Wasl dome’s construction also presented a number of unique engineering and construction challenges. These included ensuring perfect alignment of each of the pieces of pre-moulded steel trellising to each other, with a margin of error of less than five millimetres. To ensure the same, the construction teams employed state-of-the-art laser surveying and scanning equipment to ensure precision in each of the Al Wasl dome’s 873 on-site welds. To make the dome a stable structure, more than 1,200 tonnes of temporary steel columns and 520 cubic metres of concrete foundations were required to support the steel trellis during construction. The Al Wasl dome also transforms into a 360-degree projection surface with projections visible both from within and outside the dome, providing an unparalleled experience for visitors.

After months of planning and intricate and complex construction operation, the final piece of Al Wasl dome was lifted and put into place on September 19, 2019 in Dubai. The dome’s huge steel crown was positioned at the top of the jewel of the Expo 2020 Dubai site in an inspiring feat of precision engineering.

Enclosing a space of 724,000 cubic metres and standing tall at 67.5 metres – higher than the Leaning Tower of Pisa – the 130-metre-wide domed steel trellis encircles the Al Wasl Plaza, a structure that will be the heart of the Expo 2020 site and set to become Dubai’s latest architectural landmark.

His Highness Sheikh Ahmed Bin Saeed Al Maktoum, Chairman of the Expo Dubai 2020 Higher Committee, President, Dubai Civil Aviation Authority, Chairman, Dubai Airports, Chairman and Chief Executive, Emirates Airline and Group, lauded the feat saying, “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.”

The highly intricate operation, involving hundreds of on-site technicians who used special lifting equipment, was a unique engineering challenge, according to the man responsible, 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. Crowning the Al Wasl dome was both incredibly exciting and one of the most challenging engineering operations in the world. 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,” he said.

During Expo 2020, the Al Wasl dome with its 360-degree projection surface would provide an unparalleled experience for millions of visitors. 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.

To retain the geometry of the trellis structure as it was lifted, a series of tension cables was installed, connecting the perimeter of the trellis crown to a central temporary compression ring. Multiple test lifts were conducted to measure the movement of the structure as it was lifted off the ground. The tensioned cables were adjusted until the trellis perimeter connection points were in the positions required for the full lift to commence.

The crowning of the Al Wasl dome’s was the culmination of 14 months of preparation, beginning on June 26, 2018. It is not only an engineering and technological feat, but also an epitome of collaboration, which brought pieces and people from different parts of the world together to execute a marvellous piece of architecture, design and advancement.