CAPITAL TOWER ABU DHABI :
Great cities need great buildings. Over time, these iconic buildings become visual statements of the era and the place they represent.
Capital Gate, the focal point of Capital Centre, was conceived to provide Abu Dhabi, the capital of the United Arab Emirates (UAE), with a signature tower that signifies the city’s progress and evolution. At the same time, Capital Gate pays tribute to the legacy of His Highness Sheikh Zayed Bin Sultan Al Nahyan, the late President of the UAE and the Father of the Nation.

Capital Gate’s distinctive futuristic design, aesthetic splendour and technical excellence makes it a modern marvel and a celebration of human achievement that reflects the dynamism of Abu Dhabi. Additionally, the tower provides a historic link to the past by integrating with the grandstand at the Abu Dhabi National Exhibition Centre, one of the world’s most modern exhibition venues. This grandstand was much loved by Sheikh Zayed and used by him to view National parades and celebrations. Capital Gate underscores the bond between the old and the new by linking to this historic grandstand through an innovative canopy commencing from level 18 of the tower and sweeping across the grandstand, creating a wave-like effect.

FACT FILE

 ADNEC (Abu Dhabi National Exhibitions Company) is the owner and developer of Capital Gate.
The iconic tower soars 160 metres above ground and has been built with a westward incline of 18 degrees.
Capital Gate holds the Guinness Record for ‘World’s Furthest Leaning Manmade Tower’.
Capital Gate contains 35 storeys with floors 2 - 16 comprising office space. Floors 18 onwards will house the 189-room, exclusive ‘Hyatt Capital Gate’ hotel. Floors 1 & 17 comprise plant rooms.
Total Built-up Area: 53,100 sqm
Total Office Area: 20,900 sqm
Total Hotel Area: 25,050 sqm
Approximately 7,000 m3 of concrete used in the foundation, which contains 490 piles drilled up to 30m deep.
Approximately 8,500 structural steel diagrids/beams/columns/embedment plates used on the tower.
More than 12,500 different glass panes form more than 720 distinct diamond-shapes on the tower’s external façade.
Each ‘diamond’ weighs approximately 5 tons and contains 18 glass panes.
In total, 21,000 sqm of glass has been used in the façade.
Total number of man-hours worked as of September 2010 – 8.4 million.
13,200 tons of structural steel used in the tower of which 7,000 tons is used in the two diagrid systems (internal and external).
Capital Gate’s construction commenced in September 2007; the tower’s completion is scheduled for 2011.
Capital Gate forms the focal point of ADNEC’s Capital Centre master development comprising 23 towers including branded hotels, commercial buildings, residential and serviced apartment complexes and developments for mixed use. 

DESIGN

 
Nothing is standard about Capital Gate. Each room is different. Each pane of glass is different and every angle is different. It was designed to provide no symmetry so it inspires those within and outside the tower.

Capital Gate was designed to be the most recognisable icon of the ADNEC/Capital Centre development. Further, it was designed to blend seamlessly with the National Day Grandstand, breathing new life into this historic landmark for the UAE.

The eye-catching ‘splash’ commencing from level 18 and sweeping across the historic grandstand, connects the past with the new, creating a wave-like effect over the exhibition centre.
Other key design elements include:
The outdoor swimming pool on the 19th floor with a fantastic panoramic view overlooking the Sheikh Zayed mosque, the Arabian Gulf, the Mangroves, Downtown Abu Dhabi and Saadiyat and Yas Island.
The cantilevered tea lounge which overhangs the outside of the tower 80m above the ground
The tapered internal atrium, which itself is formed by a separate structural steel diagrid over 60m in height (from floor 19 to the roof) creates a stunning internal space that is quite unprecedented, and which brings natural daylight deep inside the building

SUSTAINABILITY

The double-glazed façade is used to achieve greater energy efficiency. Waste air is pre-cooled in between the inner and outer façade thereby reducing the energy consumption of the building by recycling the used air.
The glass used on the tower’s façade is a low emissivity glass never before used in the UAE. It’s designed to keep the inside of the building cool and eliminate glare, while maintaining the transparency of the façade - an important design consideration.
The stainless steel ‘splash’ is a shading device that eliminates over 30 percent of the sun’s heat before it ever reaches the building, thereby saving on the need for cooling within the building. The splash twists around the building towards the south to shield Capital Gate as much as possible from direct sunlight. 

STRUCTURE

   
From its foundations right through its pinnacle, Capital Gate is a unique building and among the most technically challenging engineering projects in the world.
Some key features stand out amongst others:
It’s gravity-defying 18 degree lean, widely believed to be the most inclined in the world
The continuous twist of its form which ensures that the tower looks different from every angle
The unique nature of the floor plate, each floor is unique

The foundation contains an incredibly dense mesh of reinforced steel that sits above 490 piles, drilled 30 meters underground to accommodate gravitational, wind and seismic pressures.

The core of the building is a pre-cambered, ‘slanting’ core that pulls in the opposite direction to the lean. It straightens as the building grows, pulled into a vertical position by the change in the centre of gravity of the building as concrete was poured onto subsequent floors.
The floor plates up to the 12th level are stacked vertically over one another. Between levels 12th and 29th the floor plates stagger over each other, in relation to the lean and twist of the shell, by between 800 to 1400mm and then back to 900mm. Between the 29th storey and the top storey, the range is between 900 and 300mm in relation to the line of the façade.
Capital Gate’s shell comprises a super-strong exo-skeleton called the diagrid, that provides a clear, unobstructed floor plate, using much less steel than a conventional structural frame. Other high-profile buildings that use the diagrid technology include the Hearst Tower in New York City, the Swiss Re building ("the Gherkin") in London and the CCTV headquarters tower in Beijing. The total weight of steel used in Capital Gate is estimated to be around 21,500 tons which compares favourably to the 50,000 tons estimated for the CCTV tower in Beijing and the 36,910 tons of steel used in Malaysia’s Petronas Towers in Kuala Lumpur.