Burj Dubai

Un article de Vev.

Modèle:Building under construction Modèle:Infobox Skyscraper

Burj Dubai (Modèle:Lang-ar "Dubai Tower") is a supertall skyscraper currently under construction in Dubai, United Arab Emirates. When it is completed in late 2008, it is predicted to be the tallest man-made structure in the world, as well as the tallest building by any measure. Scheduled for occupancy in September 2009, the building is part of a Modèle:Km2 to mi2 development called 'Downtown Burj Dubai' and is located at the "First Interchange" (aka "Defence Roundabout") along Sheikh Zayed Road at Doha Street.

The building is being built mainly by South Korean company Samsung, along with the Belgian company Besix and the UAE company Arabtec. It was designed by American Adrian Smith before he left Skidmore, Owings and Merrill LLP (SOM) of Chicago to start his own independent practice, [[Adrian Smith + Gordon Gill Architecture]] in October 2006.<ref> Architect Magazine: Adrian Smith Leaves SOM, Longtime Skidmore partner bucks retirement to start new firm

.</ref> However, SOM continues to lead the architectural, structural engineering and mechanical engineering of Burj Dubai. The total budget for the Burj Dubai project is about $4.1 billion US and for the entire new 'Downtown Burj Dubai', $20 billion US.

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Height

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Current height and timeline of events

As of 24 October 2007, Burj Dubai has reached a height of Modèle:M to ft, with 156 completed floors.<ref name="official site"> Burj Dubai Official Website

. Retrieved on 2007-12-06. </ref>

Burj Dubai's last two milestones will be to surpass the Modèle:M to ft height of the KVLY-TV Mast in North Dakota, United States to become the world's tallest structure, and to pass the Warsaw radio mast in Gąbin, Poland (Modèle:M to ft until it collapsed in 1991) to become the world's tallest structure of any type ever built.

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 Modèle:M to ft, surpassing the Modèle:M to ft to which concrete was pumped during the construction of Taipei 101.<ref>Burj Dubai:Unimix sets record for concrete pumping</ref>
July 21 2007
Burj Dubai becomes the tallest building on Earth surpassing Taipei 101 which stands at a height of Modèle:M to ft.<ref name="official site"> The previous day, the head of the Council on Tall Buildings and Urban Habitat (CTBUH), Antony Wood, had confirmed that it "surpassed the height of Taipei 101 structurally (concrete)." <ref name="CTBUH"> Burj Dubai Height Overtakes Taipei 101

. skyscrapernews.com

. Retrieved on 2007-07-22. </ref> However, he also added "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 [sic] project. Taipei 101 is thus officially the world's tallest until that happens."

August 12 2007
Burj Dubai surpassed the height of the Sears' Tower antenna which stands at a height of Modèle:M to ft.
September 3 2007
Burj Dubai becomes the second-tallest freestanding structure, surpassing the Modèle:M to ft Ostankino Tower in Moscow, Russia.
September 12 2007
At Modèle:M to ft, Burj Dubai becomes the world's tallest freestanding structure, surpassing the CN Tower in Toronto, Canada.<ref name = "cbc20070912">"

   CN Tower dethroned by Dubai building 
     
 " , The Canadian Broadcasting Corporation
  , September 12, 2007
 
  . Retrieved on 2007-09-13
 .  (English) 
  </ref>

December 10 2007
The steel construction of the Burj Dubai begins. At this point, no more structural concrete will be used. The number of floors nor the current height have been released officially for two months.

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Current records

Note: As indicated above, the CTBUH does not recognise records for buildings still under construction, therefore some of those records are unofficial:

Tallest freestanding structure: Modèle:M to ft (previously CN Tower - Modèle:M to ft)
Building with most floors: 156 (previously Sears Tower / World Trade Center - 110)
Vertical concrete pumping (for a building): Modèle:M to ft (previously Taipei 101 - Modèle:M to ft)
Vertical concrete pumping (for any construction): Modèle:M to ft (previously Riva del Garda Hydroelectric Power Plant - Modèle:M to ft<ref>Putzmeister - History - 1994 - World record: 532 m</ref>)

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Projected height

Image:BurjDubaiHeight.png

Projected height of the completed Burj Dubai, compared to the height of some other well known tall buildings.

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 Modèle:M to ft.<ref>Project information, doka- The Formwork Experts, retrieved 2006-05-04</ref> Based on this height, the total number of habitable floors is expected to be around 160. However, when pressed for a more precise figure, the project manager merely repeated that he was able only to guarantee that the final height would be higher than Modèle:M to ft, and it would be the world's tallest free-standing structure when completed.

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History of height increases

Though unconfirmed, Burj Dubai has been rumoured to have undergone several height increases since its inception. Originally proposed as a virtual clone of the Modèle:M to ft Grollo Tower proposal for Melbourne, Australia's Docklands waterfront development, the tower was redesigned with an original design by Skidmore Owings and Merrill (SOM) seen above and discussed below. This design should put it at approximately Modèle:M to 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<ref>burjdubaiskyscraper.com</ref> mentions a rumoured final height of Modèle:M to ft in a September 28, 2006 posting, but this is contradicted by a September 20, 2006 article listing a height over Modèle:M to ft.<ref>"

   Builder: Dubai High-Rise World's Tallest 
     
 " , AP News
  . Retrieved on 2007-07-22
 . </ref>

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,<ref>Modèle:PDFlink Cityscape, 2005-09-18, retrieved 2006-05-05</ref>, 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 the height cannot be changed.

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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 and/or construction.

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 Modèle:M to ft in height with 200 floors.<ref>http://www.emporis.com/en/wm/bu/?id=murjantower1-manama-bahrain</ref>

Also potentially competing with Burj Dubai is the proposed Modèle:M to 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.<ref>"Architects plan kilometre-high skyscraper", by Will Knight, NewScientist.com, December 9, 2005, retrieved 2006-03-25</ref>

Another proposed tower which may surpass the height of Burj Dubai, is Al Burj ("The Tower"). If built, it will form the centrepiece of Dubai Waterfront, the world's largest waterfront development situated only Modèle:Km to mi from the Burj Dubai site. Speculation has suggested various heights between Modèle:M to ft and Modèle:M to ft, but the developer is keeping the final height tightly under wraps.

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Architecture and design

The tower is being constructed by a South Korean company, Samsung Engineering & Construction <ref name="Samsung E&C"> Samsung E&C Projects

. </ref> which also built the Petronas Twin Towers and the Taipei 101. 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 <ref name="GHD Projects"> GHD Projects

. </ref> , an international multidisciplinary consulting firm, to assist with the design, review and assessment involved in the construction process.

Image:Comparisonfinal001fx7.png

Supertall cross-section comparisons

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 desert flower hymenocallis native to the region. 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.

The exterior cladding of Burj Dubai will consist of reflective glazing with aluminum and textured stainless steel spandrel panels with vertical tubular fins of stainless steel. 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). Corporate offices and suites will fill most of the remaining floors, except for a 123rd floor lobby and 124th floor (about Modèle:Formatnum:440 metres ({{formatnum:{{rnd/+|440*1/0.3048|0|Modèle:Rnd/00}}}} ft)) indoor/outdoor observation deck. The spire will also hold communications equipment. An outdoor zero-entry swimming pool will be located on the 78th floor of the tower.

It will also feature the world's fastest elevator, rising and descending at Modèle:Convert/m:s.<ref>Burj Dubai will have world's highest elevator installation, by Moushumi Das Chaudhry, BurjDubaiSkyscraper, 2006-03-12, retrieved 2006-03-25</ref> The world's current fastest elevator (in the Taipei 101 office tower in Taipei) travels at Modèle:Convert/m:s. Engineers had considered installing the world's first triple-decker elevators, but the final design calls for double-deck elevators.<ref name="emporis"> Burj Dubai, Dubai, at emporis.com

. Retrieved on 2007-05-23. </ref> A total of 56 elevators will be installed that can carry 42 people at a time. <ref name="elevator">Burj Dubai reaches a record high. EMAAR, 2007-07-21, retrieved 2007-07-23</ref>

Engineers rotated the building 120 degrees from its original layout to reduce stress from prevailing winds. Over Modèle:M3 to yd3 of concrete, weighing more than Modèle:Convert/M/T were used to construct the concrete and steel foundation, which features 192 piles buried more than Modèle:M to ft deep.<ref name="emporis"/>

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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, Modèle:Km2 to mi2 of parkland, at least 19 residential towers, the Dubai Mall, and the Modèle:Km2 to mi2 man-made Burj Dubai Lake. Burj Dubai will cost US$ 800 million to build and the entire Modèle:Km2 to mi2 development will cost around US$ 20 billion.

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.<ref>"In Dubai, the Sky's No Limit", by Megan K. Stack, Los Angeles Times, 2005-10-13, retrieved 2006-03-26</ref>

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Construction

Image:Burj Dubai in Skyline on 8 July 2007.jpg

Burj Dubai in July 2007

Burj Dubai is made from reinforced concrete. 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 Modèle:M to ft. Burj Dubai now holds this record as of August 19, 2007, as it has a height of Modèle:M to ft, to hold the record for concrete pumping on any project; and as of October 2, 2007 concrete was pumped to a delivery height of Modèle:M to ft.<ref name="Putzmeister"> Putzmeister AG - News - Burj Dubai

. </ref>

Special mixes of concrete are made to withstand the extreme pressures of the massive weight of the tower; 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.

As the consistency of the concrete on the project is essential, it was difficult to create a concrete which could withstand the thousands of tonnes bearing down on it, but also to withstand Gulf temperatures which can reach Modèle:C to 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.

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Labour controversy

Modèle:Further Burj Dubai is being built primarily by immigrant engineers and workers from Pakistan, India, Bangladesh, China and the Philippines.<ref name="breitbart" /> Press reports indicate that skilled carpenters at the site earn US$7.60 (£4.34)/day, and laborers earn US$4.00 (£2.84).<ref name="breitbart">"Workers Riot at Site of Dubai Skyscraper", Jim Krane, breitbart.com, 2006-03-22, retrieved March 24, 2006</ref><ref>Riot by migrant workers halts construction of Dubai skyscraper, by Brian Whitaker and agencies, The Guardian, 2006-03-23, retrieved 2006-03-25</ref> Unions were forbidden in the United Arab Emirates up until recently, when the government announced steps to allow construction unions.<ref>"UAE to allow construction unions", BBC News, 2006-03-30, retrieved 2006-04-20</ref> 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 (£488k) 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 the Burj Dubai and other Dubai construction projects.

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