Burj KhalifaTower

Burj Khalifa (Arabic: برج خليفة‎, "Khalifa Tower") is a very tall skyscraper in Dubai, United Arab Emirates and is the tallest building ever built, at 828 metres (2,717 feet). Before the buildingopened, it was called Burj Dubai. The building is 162 stories high. Construction of the tower was started in 2004. The building was officially opened on 4 January 2010.[2][3] It is the tallest structure made by humans in the world. The building is more than 300 metres (980 feet) taller than Taipei 101. Taipei 101 was the tallest building until 2010 before Burj Khalifa was built.
Adrian Smith designed the tower.[4] He worked with Skidmore, Owings and Merrill (SOM) until 2006. It was built by Samsung Engineering & Construction, Besix, and Arabtec.The tower cost usa1.5 billion to build..The building is part of a 2 kilometres (1.2 miles) building project on Sheikh Zayed Road, Downtown Burj Khalifa. It is near Dubai's main business district.

The building and planning

The main contractor was Samsung C&T of South Korea. They also built the Taipei 101and Petronas Twin Towers.[8] Other contractors who helped with the building included Belgian group Besix and Arabtecfrom the UAE. The Turner Construction Company was chosen as the construction project manager.[9]
The design architect, Adrian Smith, did not like the first design of the upper part of the building. He added 27 new floors and an aluminium spire to the top of the plans. The design of Burj Khalifa based on those used in Islamic architecture. Burj Khalifa has been said to have had several other planned height increases since it was first built. This has not been proven to be true yet. The TV/radiocommunications mast was added to the tower's plans in 2007. This was after building work had begun in 2006. There are pressurized, air-conditioned refuge floorsabout every 35 floors. These were put into the tower in case of an emergency or fire.[10]
The unusual design and engineering problems of building Burj Khalifa have been shown in many television documentaries. These include the Big, Bigger, Biggest series on the National Geographic and Five channels, and the Mega Builders series on the Discovery Channel.The most important building material of Burj Khalifa is reinforced concrete. A special concrete was needed because of the high pressures of the building's weight and the hot local climate of Persian Gulf temperaturesthat can reach 50 °C (122 °F). Any major cracks could have caused a large amount of damage to the building.
The foundation of the building is 15 metres (49 feet) deep. It was built with 192 columnsbeing put into the ground. Each column was 1.5 metres (4 feet 11 inches) in diameter and 43 metres (141 feet) long.[11] 55,000 tonnes (121,000,000 pounds) of steel rebar was used in the construction of the tower. It took 22 million man-hours to build.[12] A high density, low permeability concrete was used in the foundations of Burj Khalifa. A cathodic protection system is used to lessen any bad effects from corrosive chemicals in local ground water.

Delays and late building work

Emaar Properties said on 9 June 2008 that construction of Burj Khalifa was slowed because of changes to finishes. An Emaar official said that the luxury finishes that were decided on in 2004, when the tower was first planned, were being being replaced by better finishes. The design of the apartments were also made better. This was done to make them both look better and work better.[15]There were problems with the marbledecorations, flooring, the top floors' sanitationsystem, broken glasswork and a poorly done wall mural of the Sultan of Oman. A new ending date of 2 December, 2009, was then given.[16] Burj Khalifa opened on 4 January 2010.[17][18]

Workers' disputes and strikes.

Burj Khalifa was built mainly by people from South Asia.[19][20] Press reports said in 2006 that skilled carpenters at the site earned UK£4.34 a day, and labourers earned UK£2.84.[According to a BBC investigation and a Human Rights Watch report, the workers lived in very bad conditions. Often they were not paid for the work. Their passports were taken by their employers. It was said that they were working in dangerous conditions that caused high number of deathsand injuries.[21] Companies not paying workers has been reported to the authoritiesseveral times.
On 21 March 2006, about 2,500 workers protested. They were mad about buses that were delayed for the end of their shifts. They damaged cars, offices, computers, and construction equipment.[19] A Dubai Interior Ministry official said they caused almost UK£500,000 in damage.[19] Most of the workers who were part of the riot returned the following day but would not work.[19]

Records set
Play media
A cartoon animation of construction process.
The building is not only the tallest structure in the world, it also holds the following records-

Tallest skyscraper to top of spire: 828 m (2,717 ft) (previously Taipei 101 – 509.2 m (1,671 ft))
Tallest structure ever built: 828 m (2,717 ft) (previously Warsaw radio mast – 646.38 m (2,121 ft))
Tallest freestanding structure: 828 m (2,717 ft) (previously CN Tower – 553.3 m (1,815 ft))
Building with most floors: 160 (previously Willis Tower – 108)[22]
World's highest elevator installation[23]
World's fastest elevators at speed of 64 km/h (40 mph) or 18 m/s (59 ft/s)[23](previously Taipei 101 – 16.83 m/s)
Highest vertical concrete pumping (for a building): 606 m (1,988 ft)[24] (previously Taipei 101 – 449.2 m (1,474 ft))
Highest vertical concrete pumping (for any construction): 606 m (1,988 ft)[24](previously Riva del Garda Hydroelectric Power Plant – 532 m (1,745 ft)[25])
The first world's tallest structure in history to include residential space[11]
Highest outdoor observation deck in the world (124th floor), at about 440 m (1,440 ft).[26]
World's highest installation of an aluminum and glass façade, at a height of 512 m (1,680 ft).
World's highest swimming pool (76th floor)[27]
Worlds highest restaurant (122nd floor).