Capital Gate is a skyscraper in Abu Dhabi adjacent to the Abu Dhabi National Exhibition Centre designed with a striking lean. At 160 m (520 ft) and 35 stories, it is one of the tallest buildings in the city and features an 18° incline to the west. The owner and developer of Capital Gate is Abu Dhabi National Exhibitions Company. The tower (also known as the Leaning Tower of Abu Dhabi) is the focal point of the Capital Center/Abu Dhabi National Exhibition Centre master development.
In June 2010, Guinness World Records certified Capital Gate as the “World’s furthest leaning man-made tower.” The new record shows that the Capital Gate tower has been built to lean 18° westwards; more than four times that of the Leaning Tower of Suurhusen. Investigation and evaluation, which was made by a Guinness appointed awards committee, started in January 2010, when the exterior was completed. The gravitational pressure caused by the 18° incline is countered by a technique called pre-cambered core, using a core of concrete reinforced with steel, with the core deliberately built slightly off-center. It is also anchored to the ground by 490 piles which are drilled 20–30 meters underground.
The building has a diagrid especially designed to absorb and channel the forces created by wind and seismic loading, as well as the gradient of Capital Gate. Capital Gate is thought to be the Middle East’s first building to use a diagrid; others around the world include London’s 30 St Mary Axe (Gherkin), New York’s Hearst Tower and the Beijing National Stadium.
The Capital Gate project was able to achieve its inclination through an engineering program that allows floor plates to be stacked vertically up to the 12th storey, and staggered over each other by between 300 mm to 1400 mm, which allows for the tower’s lean.
