Iconic and avant-garde, Capital Gate blends beauty with technical advancement.
The centuries-old Leaning Tower of Pisa - which began to lean shortly after it was built in 1173 - has a new rival in the shape of the 160-metre-high Capital Gate building in Abu Dhabi. The tower, with its 18 inch westward incline, has been officially recognised as the ‘furthest-leaning man-made tower’ in the world by Guinness World Records.
Standing tall, the Capital Gate tower is the cornerstone development of Abu Dhabi National Exhibition Centre’s (ADNEC) Capital Centre, a 23-tower, US$2.2 billion mixed-use “micro-city.” It has been built by combining the post tensioning and pre-cambered core techniques. The 35-storey building is made up of over 15,000 cu m of reinforced concrete and 100,000 tonne of steel and, took more than three years to complete.
The façade of the building has been constructed using 700 diamond shaped glass panels which form a dual diagrid system; Hyatt Capital Gate is the first building in Abu Dhabi to use this technology. The heaviest individual diagrid weighs 16.5 tonne. It has been created with 8,500 structural steel beam, but uses less steel than conventional frames, reducing costs and benefiting the environment. It is the same technology used for London’s “Gherkin,” and the Hearst Tower in New York.
The design of the building, pioneered by Abu Dhabi National Exhibitions Company - owner and developer, posed a number of challenges; from the structural support to interior design.
Many aspects related to this iconic tower present design challenges as there are no rectangular interior floor spaces. In addition, every single floor plate has a slightly different shape from the level below or above.
To create the curve, floor plates are stacked vertically upto the 12th storey, staggered until the 29th by 800 to 1400 mm in relation to the shell. From the 29th to the 35th floors they range between 900 and 300 mm in line with the facaed. The overturning moment this creates is countered by a large podium footprint.
To protect against gravitational, wind and seismic pressures, the foundations of the buildings are formed from 490 piles, dug upto 30 m underground and reinforced with 7,000 cu m of concrete. Above the foundations is a 2 m deep concrete base, filled with a dense mesh of reinforced steel.
Designed to mimic a wave, the building also features a ‘splash’; a completely independent steel canopy that has been fixed to the main building with I-beams. The splash also twists around the building towards the south to shield the tower as much as possible from direct sunlight. A cantilevered tea lounge overhangs the tower’s exterior, 80 m above the ground, with an internal diagrid used to create a tapered, 60 m high atrium.
The foundation contains an incredibly dense mesh of reinforced steel that sits above 490 piles, drilled 30 m underground to accommodate gravitational, wind and seismic pressures.
The convex curve of the structure seems to make the building disappear on the North West elevation. Equally on the opposite side of the building, facing south east, there will be even more dramatic bedroom views and floor cantilevered swimming pool seems to be suspended in the mid-air.
The building will comprise offices and a hotel offering city and coastline views, while providing a “sense of flotation” through the interior design and a pool which appears to be suspended in mid-air from above.
The glass panels on the outer side of the building reflect the blue colour of the sky and create a spectacular view to the visitors. A special coating of anti-ultraviolet stops the ultraviolet rays of the sun from entering the building and keeps the interior cool. The roof connecting this building and its main entrance is it’s another attraction. The bulged roof laid amidst metal rods not only gives the required shade to the visitors but also enhances the beauty of the structure.
There is also a bridge constructed connecting the Capital Tower with other buildings closer to it. Folding solar panels are installed within the structure to produce electricity so that it will be possible to fold them when the heat from the sun is very intense.
The tower’s construction commenced in September 2007 and ended in 2010. Housing a 5-star Hyatt Capital Gate hotel and approximately 20,000 sq m of office space, the tower provides a historic link to the past by integrating with this national grandstand through an innovative canopy commencing from level 18 of the tower and sweeping across the grandstand, creating a wave-like effect.
Did you know?
The Capital Gate tower’s project has been featured in an exclusive National Geographic television documentary. ‘The Leaning Tower of Abu Dhabi’ has been translated into 44 languages and will be broadcast in 166 countries.