Burj Khalifa

The building is named after the former president of the United Arab Emirates (UAE), Sheikh Khalifa bin Zayed Al Nahyan.

[11][12] The firm had designed the Sears Tower in Chicago, a previous record holder for the world's tallest building.

[13] Numerous complaints concerned migrant workers from South Asia, the primary building labour force, who were paid low wages and sometimes had their passports confiscated.

"He (Sheikh Mohammed bin Rashid Al Maktoum) wanted to put Dubai on the map with something really sensational," said Jacqui Josephson, a tourism and VIP delegations executive at Nakheel Properties.

[17] In the 2000s, Dubai started diversifying its economy but it suffered from the 2007–2008 financial crisis and the Great Recession, leaving large-scale projects already in construction abandoned.

Burj Khalifa uses the bundled tube design of the Willis Tower, invented by Fazlur Rahman Khan.

[31][32] Due to its tubular system, proportionally only half the amount of steel was used in the construction, compared to the Empire State Building.

When Adrian Smith was conceiving the project at SOM, he looked out his office window toward Lake Point Tower's curved three-wing layout and thought, "There's the prototype".

[35] According to Strabala, Burj Khalifa was designed based on the 73rd floor Tower Palace Three, an all-residential building in Seoul.

Emaar Properties also engaged GHD,[39] an international multidisciplinary consulting firm, to act as an independent verification and testing authority for concrete and steelwork.

Corporate offices and suites fill most of the remaining floors, except for the 122nd, 123rd, and 124th, where the Atmosphere restaurant, sky lobby, and an indoor and outdoor observation deck are located respectively.

[21] To wash the 24,348 windows, totaling 120,000 m2 (1,290,000 sq ft) of glass, the building has three horizontal tracks, each holding a 1,500 kg (3,300 lb) bucket machine.

[57][58] Under normal conditions, when all building maintenance units are operational, it takes 36 workers three to four months to clean the entire exterior.

The cleaning system was developed in Melbourne, Australia, by CoxGomyl, a manufacturer of building maintenance units,[60] at a cost of A$8 million.

Subsequently, on February 18, 2019, the Burj Khalifa also opened The Lounge observatory at 584 m (1,916 ft) – the highest lounge in the world,[65][66] However, in June 2016 the Shanghai Tower opened with an observation deck at a height of 561 metres, thus taking the title of the world's highest observation deck.

The Burj Khalifa's 124th floor observation deck also features a so-called electronic telescope, an augmented reality device developed by Gsmprjct° of Montréal, which allows visitors to view the surrounding landscape in real-time, and to view previously saved images such as those taken at different times of day or under different weather conditions.

[70] On 8 February 2010, the observation deck was closed to the public for two months after power-supply problems caused an elevator to become stuck between floors, trapping a group of tourists for 45 minutes.

[90] Under UAE law, the contractor and the engineer of record is jointly and severally liable for the performance of Burj Khalifa.

[11] In May 2008 Putzmeister pumped concrete with more than 21 MPA ultimate compressive strength of gravel to surpass the 600 metres weight of the effective area of each column from the foundation to the next 4th level, and the rest was by metal columns jacketed or covered with concrete to a then world record delivery height of 606 m (1,988 ft),[23] the 156th floor.

CTLGroup, working for Skidmore, Owings and Merrill, conducted the creep and shrinkage testing critical for the structural analysis of the building.

[6] The project's completion coincided with the Great Recession, and with vast overbuilding in the country, leading to high vacancies and foreclosures.

[114] With Dubai mired in debt from its huge ambitions, the government was forced to seek multibillion-dollar bailouts from its oil-rich neighbor Abu Dhabi.

[4][115] Because of the slumping demand in Dubai's property market, the rents in the Burj Khalifa plummeted 40% some ten months after its opening.

[126][127] Nine News obtained emails from Portugal's embassy in the UAE under freedom of information laws, which indicated that the female tourist jumped from the 148th floor of the Burj Khalifa.

[129][130] This is generally because the current generation of UAE locals prefer governmental jobs and do not have an attitude favouring private sector employment.

[129] According to a BBC investigation and a Human Rights Watch report, the workers were housed in abysmal conditions, and worked long hours for low pay.

[133] In March 2006 about 2,500 workers, upset over buses that were delayed for the end of their shifts, protested and triggered a riot, damaging cars, offices, computers, and construction equipment.

[139][140] The Emaar New Year's Eve fireworks celebration originated in 2010 with the inauguration of the world's tallest building, Burj Khalifa.

[149] The building has been used by several experienced BASE jumpers for authorised and unauthorised BASE jumping: In May 2008, Hervé Le Gallou and David McDonnell, dressed as engineers, entered Burj Khalifa (around 650 metres (2,130 ft) at the time), and jumped off a balcony situated several floors below the 160th floor.

[152][153] On 21 April 2014, with permission of the authorities and support from several sponsors, highly experienced French BASE jumpers Vince Reffet and Fred Fugen broke the Guinness world record for the highest BASE jump from a building after they leapt from a specially designed platform, built at the very top of the pinnacle, at 828 metres (2,717 feet).

Cross-section comparisons of various towers, from ground level to top: Burj Khalifa, Taipei 101 , Willis Tower , and the original World Trade Center
The spiral minaret at the Great Mosque of Samarra
View of The Dubai Fountain from the observation deck
View from the observation deck
Animation of construction process
Aerial closeup of Burj Khalifa under construction in March 2008
Burj Khalifa and skyline of Dubai, 2010