1. Construction
     Project timeline    Foundation    Core of the structure    Superstructure  

2. World record

3. Architecture and design

4. See also

5. References

6. External links

Capital Gate, also known as the Leaning Tower of Abu Dhabi, is a skyscraper in Abu Dhabi that is over {{convert|160|m|ft|sp=us}} tall, 35 stories high, with over {{convert|16,000|m2|sp=us}} of usable office space.^[1] Capital Gate is one of the tallest buildings in the city and was designed to incline 18° west.^[2] The building is owned and was developed by the Abu Dhabi National Exhibitions Company. The tower is the focal point of Capital Centre.

Construction

Project timeline

• {{timeline-event|date={{start date|2007|09}}|event=Start.}}
• {{timeline-event|date={{start date|2007|11}}|event=Started drilling foundations.}}
• {{timeline-event|date={{start date|2008|04}}|event=Construction of core wall.}}
• {{timeline-event|date={{start date|2009|02}}|event=Facade erected.}}
• {{timeline-event|date={{start date|2009|05}}|event=Building reached a height of {{convert|100|m|sp=us}}.}}
• {{timeline-event|date={{start date|2009|06}}|event=Incline started to take shape.}}
• {{timeline-event|date={{start date|2009|10}}|event=Building reached final height of {{convert|160|m|sp=us}}.}}
• {{timeline-event|date={{start date|2009|12}}|event=Exterior core structure completed.}}
• {{timeline-event|date={{start date|2010|01}}|event=First phase of splash completed.}}
• {{timeline-event|date={{start date|2010|02}}|event=Interior construction started.}}
• {{timeline-event|date={{start date|2010|03}}|event=Started building the bridge to Abu Dhabi National Exhibition Centre.}}
• {{timeline-event|date={{start date|2010|04}}|event=Started building the atrium roof.}}
• {{timeline-event|date={{start date|2011}}|event=Construction completed.}}
• {{timeline-event|date={{start date|2011|12|21}}|event=Opening.}}

Foundation

The structure rests on a foundation of 490 pilings that have been drilled {{convert|30|m|sp=us}} below ground. The deep pilings provide stability against strong winds, gravitational pull, and seismic pressures that arise due to the incline of the building. Of the 490 pilings, 287 are {{convert|1|m|sp=us}} in diameter and {{convert|20|to|30|m|ft|sp=us}} deep, and 203 are {{convert|60|cm|in|sp=us}} in diameter and {{convert|20|m|ft|sp=us}} deep. All 490 piles are capped together using a densely reinforced concrete mat footing nearly {{convert|2|m|ft|sp=us}} deep. The piles were initially compressed during construction to support the lower floors of the building. Now they are in tension as additional stress caused by the overhang has been applied.^[3]

Core of the structure

The core of the Capital Gate was built using jumping formwork, also known as climbing formwork. The center concrete core had to be specially designed to account for the immense forces created by the building's angle of elevation, or camber. The core contains {{convert|15,000|m3|cuyd|sp=us}} of concrete reinforced with 10,000 metric tons of steel and uses vertical post-tension and was constructed with a vertical pre-camber. This pre-camber means the core was constructed with a slight opposite lean. As each floor was installed, the weight of the floors and diagonal grid, or diagrid, system pulled the core and slowly straightened it out. The core contains 146 vertical steel tendons, each {{convert|20|m|ft|sp=us}} long, which are used for post-tension.^[3]

Superstructure

Given the 18° lean of the building, the construction required two diagrid systems: an external diagrid defining the tower's shape and an internal diagrid linked to the central core by eight unique, pin-jointed structural members. The external diagrid comprises 720 sections of varying shapes, as it is based on the direction in which the tower leans. The external grid carries the weight of the floor while the internal diagrid connects with the external and transfers the load to the core, thereby eliminating the need for columns in the floor.^[3]

World record

In June 2010, Guinness World Records recognized Capital Gate tower as the world's "farthest manmade leaning building".^[4][5] The new record shows that the Capital Gate tower has been built to lean 18° west, which is more than four times that of the Leaning Tower of Suurhusen.{{citation needed|date=December 2018}} The Guinness World Records recognition was given by a Guinness-appointed awards committee in January 2010, when the exterior was completed.{{citation needed|date=December 2018}}

Architecture and design

The building has a diagrid specially designed to absorb and channel the forces created by wind and seismic loading, as well as the gradient of Capital Gate. Capital Gate is one of only a handful of diagrid buildings in the world. Others include London's 30 St Mary Axe (Gherkin), New York's Hearst Tower, and Beijing's National Stadium.^[6]

The Capital Gate project was able to achieve its inclination through an engineering technique, known as pre-cambering, that allows floor plates to be stacked vertically up to the 12th story and staggered, one over another, between {{convert|300|to|1400|mm|in|sp=us}}. The gravitational pressure caused by the 18° incline is countered by the pre-cambering, 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 {{convert|20|to|30|m|ft|sp=us}} underground.^[7]

Capital Gate was designed by architectural firm RMJM and was completed in 2011. The tower includes {{convert|16,000|m2|sp=us}} of office space and the Andaz Hotel on floors 18 through 33.^[8]

See also

• List of leaning towers
• List of tallest buildings in Abu Dhabi
• Diagrid
• List of twisted buildings

References

External links

• Capital Gate official website
• Capital Gate Tower at CTBUH website
• [https://www.rmjm.com/the-architects-perspective-the-capital-gate/ The Architects Perspective - The Capital Gate]
• [https://www.archdaily.com/889854/capital-gate-rmjm the Capital Gate - rmjm]

• Randøy Bridge
• Ranea
• Rane Arroyo
• Raneces
• Ranee (disambiguation)
• Ranee Narah
• Ranefer
• Raneferef
• Ranefer (High Priest of Ptah)
• Raneh Fall
• Raneh Falls
• Ranelagh, Ontario
• Ranelagh School
• Ranelie Cain
• Ranella australasia
• Ranella bufonia
• Ranella gemmifera
• Ranella lampas
• Ranella olearius
• Ranen
• Ranenburg
• RAN Ensign
• Rane Pro Audio
• Raner C. Collins
• Raner Christercunean Collins