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Height

Current height

As of 12 May 2008, Burj Dubai had reached a height of 636 m (2,087 ft), with 160 completed floors.^[9]

Burj Dubai's final milestone will be to surpass the Warsaw radio mast in Konstantynów near Gąbin, Poland (which stood at 646.4 m (2,121 ft) until it collapsed in 1991) to become the world's tallest structure of any type ever built.

Timeline of events

• September 21, 2004
  Emaar contractors begin construction of Burj Dubai.
• February 2007
  Burj Dubai surpasses the Sears Tower as the building with the most floors.
• May 13, 2007
  Burj Dubai sets record for vertical concrete pumping on any building at 452 m (1,483 ft), surpassing the 449.2 m (1,474 ft) to which concrete was pumped during the construction of Taipei 101.^[10]
• July 21, 2007
  Burj Dubai surpasses Taipei 101 which stands at a height of 509.2 m (1,671 ft) and was the tallest building on Earth. ^[11]
• August 12, 2007
  Burj Dubai surpassed the height of the Sears Tower antenna which stands at a height of 527.3 m (1,730 ft).
• September 3, 2007
  Burj Dubai becomes the second-tallest freestanding structure, surpassing the 540 m (1,772 ft) Ostankino Tower in Moscow.
• September 12, 2007
  At 555.3 m (1,822 ft), Burj Dubai becomes the world's tallest freestanding structure on land, surpassing CN Tower in Toronto.
• April 7, 2008
  Emaar announces that Burj Dubai, at 629 m (2,064 ft), has surpassed the KVLY-TV Mast to become the tallest man-made structure on earth.
• June 17, 2008
  Emaar announces that Burj Dubai's height is over 636 m (2,087 ft) and that its final height will not be given until September 2009 when it is completed.

Current records

• Tallest structure: 636 m (2,087 ft) (previously KVLY-TV mast - 628.8 m (2,063 ft))
• Tallest freestanding structure: 636 m (2,087 ft) (previously CN Tower - 553.3 m (1,815 ft))
• Building with most floors: 164 (previously Sears Tower / World Trade Center - 110)
• Highest vertical concrete pumping (for a building): 601.0 m (1,972 ft) (previously Taipei 101 - 449.2 m (1,474 ft))
• Highest vertical concrete pumping (for any construction): 601.0 m (1,972 ft) (previously Riva del Garda Hydroelectric Power Plant - 532 m (1,745 ft)

Note: Additional records for tallest skyscraper are considered unofficial. On July 20, 2007, the head of the Council on Tall Buildings and Urban Habitat (CTBUH), Antony Wood, said "We will not classify it as a building until it is complete, clad and at least partially open for business to avoid things like the Ryungyong project. Taipei 101 is thus officially the world's tallest until that happens."

Projected height

The projected final height of Burj Dubai is officially being kept a secret due to competition from other buildings under construction or proposed; however, figures released by a contractor on the project have suggested a height of around 818 m (2,684 ft). Based on this height, the total number of habitable floors is expected to be around 162. However, Burj Dubai's construction manager, Greg Sang, has said only that the final height would be greater than 700 m (2,297 ft), and that it would be the world's tallest free-standing structure when completed.

History of height increases

Though unconfirmed, Burj Dubai has been rumoured to have undergone several planned height increases since its inception. Originally proposed as a virtual clone of the 560 m (1,837 ft) Grollo Tower proposal for Melbourne, Australia's Docklands waterfront development, the tower was redesigned with an original design by Skidmore Owings and Merrill seen above and discussed below. This design should put it at approximately 705 m (2,313 ft). Contradictory information abounds regarding the official height of the building, which is to be expected, considering the building seeks to acquire the designation as the world's tallest structure upon completion in 2009. One website mentions a rumoured final height of 916 m (3,005 ft) in a September 28, 2006 posting, but this is contradicted by a September 20, 2006 article listing a height over 940 m (3,084 ft).

The design architect, Adrian Smith, felt that the upper-most section of the building did not culminate elegantly with the rest of the structure, so he sought and received approval to increase it to the currently planned height. It has been explicitly stated that this change did not include any added floors, which is fitting with Smith's attempts to make the crown more slender. However, the top of the tower will be a steel frame structure, unlike the lower portion's reinforced concrete. The developer, Emaar, has stated this steel section may be extended to beat any other tower to the title of tallest; however, once the tower is complete, height increases will not be recognised.

Delay

Emaar Properties announced on June 9, 2008 that construction of Burj Dubai was delayed by upgraded finishes and will be completed only in September 2009. An Emaar spokesperson said "The luxury finishes that were decided on in 2004, when the tower was initially conceptualized, is now being replaced by upgraded finishes. The design of the apartments has also been enhanced to make them more aesthetically attractive and functionally superior".^[23]

Competition with other projects

Several other major projects in the region may vie for the title of tallest structure. These other projects are in various states of planning:

• One of Burj Dubai's potential competitors is the proposed Murjan Tower, in Manama, Bahrain. Designed by the Danish architects Henning Larsens Tegnestue A/S, it is expected to be 1,022 m (3,353 ft) in height with 200 floors.^[24]

• Also potentially competing with Burj Dubai is the proposed 1,001 m (3,284 ft) Burj Mubarak al-Kabir to be erected in Kuwait as part of a massive development project called Madinat al-Hareer (City of Silk). The project also includes an Olympic stadium, residences, hotels, and retail facilities. However, the project may take 25 years to complete.^[25]

• Another proposed tower which may surpass the height of Burj Dubai, is Al Burj, on a site near Dubai Marina. Speculation has suggested various heights between 700 m (2,297 ft) and 1,400 m (4,593 ft), but the developer is keeping the final height tightly under wraps. If built, it will be only 22 km (14 mi) from the Burj Dubai site.

• The Mile-High Tower, a recently announced skyscraper planned for Jeddah, Saudi Arabia, would be almost twice as tall as Burj Dubai if completed as planned by Riyadh-based Kingdom Holdings.

Architecture and design

The tower is designed by Skidmore, Owings and Merrill, who also designed the Sears Tower in Chicago and the Freedom Tower in New York City, among numerous other famous high-rises. The building resembles the bundled tube form of the Sears Tower, but is not a tube structure. The design of Burj Dubai is reminiscent of the Frank Lloyd Wright vision for The Illinois, a mile high skyscraper designed for Chicago, Illinois. Burj Dubai is expected to rise to 150% of the height of the Sears Tower. Emaar has also engaged GHD,^[26] an international multidisciplinary consulting firm, to assist with the design, review and assessment involved in the construction process.

The design of Burj Dubai is ostensibly derived from the patterning systems embodied in Islamic architecture, with the triple-lobed footprint of the building based on an abstracted version of the flower hymenocallis. The tower is composed of three elements arranged around a central core. As the tower rises from the flat desert base, setbacks occur at each element in an upward spiralling pattern, decreasing the cross section of the tower as it reaches toward the sky. At the top, the central core emerges and is sculpted to form a finishing spire. A Y-shaped floor plan maximizes views of the Persian Gulf. Viewed from above or from the base, the form also evokes the onion domes of Islamic architecture. During the design process, engineers rotated the building 120 degrees from its original layout to reduce stress from prevailing winds. The tower, at its tallest point, sways a total of 3.35 metres (9.3ft).^{[citation needed]}

The exterior cladding of Burj Dubai will consist of 142,000 m² (1,528,000 sq ft) of reflective glazing, and aluminium and textured stainless steel spandrel panels with vertical tubular fins. The cladding system is designed to withstand Dubai's extreme summer temperatures.

The interior will be decorated by Giorgio Armani. An Armani Hotel (the first of its kind) will occupy the lower 37 floors. Floors 45 through 108 will have 700 private apartments on 64 floors (which, according to the developer, sold out within eight hours of going on sale). An outdoor zero-entry swimming pool will be located on the 78th floor of the tower. Corporate offices and suites will fill most of the remaining floors, except for a 123rd floor lobby and 124th floor (about 440 m (1,444 ft)) indoor/outdoor observation deck. The spire - itself over 200 m (700 ft) tall - will hold communications equipment.

It will also feature the world's fastest elevator, rising and descending at 18 m/s (59 ft/s). The world's current fastest elevator (in the Taipei 101) travels at 16.83 m/s (55.2 ft/s). Engineers had considered installing the world's first triple-decker elevators, but the final design calls for double-deck elevators. A total of 56 elevators will be installed that can each carry 42 people at a time.

Outside, and at a cost of Dh 800 million (US $ 217 m), a record setting fountain system is to be designed by WET Design, the California-based company responsible for the fountains at the Bellagio Hotel Lake in Las Vegas. Illuminated by 6,600 lights and 50 colored projectors, it will be 275 m (900 ft) long and will shoot water 150 m (490 ft) into the air, accompanied by a range of classical to contemporary Arabic and world music.

Construction

The tower is being constructed by a South Korean company, Samsung Engineering & Construction^[29] which also built the Petronas Twin Towers and the Taipei 101.

The primary structural system of Burj Dubai is reinforced concrete. Over 45,000 m³ (58,900 cu yd) of concrete, weighing more than 110,000 tonnes (120,000 ST/110,000 LT) were used to construct the concrete and steel foundation, which features 192 piles buried more than 50 m (164 ft) deep.^[1] When completed, Burj Dubai's construction will have used 330,000 m³ (431,600 cu yd) of concrete and 39,000 tonnes (43,000 ST/38,000 LT) of steel rebar (enough to extend over a quarter of the way around the world if laid end-to-end); and construction will have taken 22 million man hours.

As construction of the tower progresses, it becomes increasingly difficult to vertically pump the thousands of cubic metres of concrete that are required. The previous record for pumping concrete on any project was set during the extension of the Riva del Garda Hydroelectric Power Plant in Italy in 1994, when concrete was pumped to a height of 532 m (1,745 ft). Burj Dubai now holds this record as of August 19, 2007, as it has a height of 536.1 m (1,759 ft), to hold the record for concrete pumping on any project; and as of November 8, 2007 concrete was pumped to a delivery height of 601 m (1,972 ft).^[30]

Special mixes of concrete are made to withstand the extreme pressures of the massive weight of the tower; as typical with reinforced concrete construction, each batch of concrete is tested and checked to see whether it can withstand certain pressures. The head of Concrete Quality Checking on the Burj Dubai project is Alam Feroze, who is in charge of concrete on the whole project. The concrete pumps, pipelines and booms are provided by Putzmeister AG, of Aichtal, Germany.

The consistency of the concrete on the project is essential. It was difficult to create a concrete that could withstand the thousands of tonnes bearing down on it and also withstand Gulf temperatures that can reach 50 °C (122 °F). To combat this problem, the concrete is not poured during the day. Instead, ice is added to the mixture and it is poured at night when it is cooler and the humidity is higher. A cooler concrete mixture cures evenly throughout and therefore is less likely to set too quickly and crack. Any significant cracks could put the whole project in jeopardy.

The unique design and engineering challenges of building Burj Dubai, have been featured in a number of TV documentaries, including the "Big, Bigger, Biggest" series on the National Geographic Channel in the USA, and Five in the United Kingdom, and the "Mega Builders" series on the Discovery Channel.

Labour controversy

Burj Dubai is being built primarily by immigrant engineers and workers from Pakistan, India, Bangladesh, China and the Philippines. Press reports indicate that skilled carpenters at the site earn US$7.60/day, and laborers earn US$4.00.^[31][32] Unions were forbidden in the United Arab Emirates up until recently, when the government announced steps to allow construction unions. On March 21, 2006, workers upset over low wages and poor working conditions rioted, damaging cars, offices, computers, and construction equipment. A Dubai Interior Ministry official said the rioters caused approximately US$1m in damage. Most workers returned the following day but refused to work. Workers building a new terminal at Dubai International Airport also joined that day's strike action.

The United Arab Emirates dirham's close connection with the low US Dollar, and the increased cost-of-living in the region, has made it increasingly difficult for immigrant construction workers to survive on their wages. An offer by the UAE government in June 2007 to fly home illegal immigrant workers free-of-charge, with no questions asked, was met with overwhelming demand, further threatening the supply of workers on Burj Dubai and other Dubai construction projects. As of June 17, 2008 there are 7,500 skilled workers employed in the construction of Burj Dubai.

Purpose

Burj Dubai has been designed to be the centerpiece of a large-scale, mixed-use development that will include 30,000 homes, nine hotels such as the Burj Dubai Lake Hotel & Serviced Apartments, 0.03 km² (0.01 sq mi) of parkland, at least 19 residential towers, the Dubai Mall, and the 0.12 km² (0.05 sq mi) man-made Burj Dubai Lake.

The silvery glass-sheathed concrete building will give the title of Earth's tallest free-standing structure to the Middle East — a title not held by the region since 1311 AD when Lincoln Cathedral in England surpassed the height of the Great Pyramid of Giza, which had held the title for almost four millennia.

The decision to build Burj Dubai is reportedly based on the government's decision to diversify from a trade-based economy to one that is service- and tourism-oriented. According to officials, it is necessary for projects like Burj Dubai to be built in the city to garner more international recognition, and hence investment. "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.

BASE Jumping

BASE Jumpers are already targeting Burj Dubai to achieve world-record jumps. There are 2 documented attempts, one by a 36-year-old British jumper and another by a 47-year-old Frenchman. The latter's attempt was hindered as he was arrested before jumping, whereas the Briton was successful in his jump, but got arrested upon landing. His altimeter showed a jump from over 600 meters.

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