From the
Peripatetic Engineer:
Burj Dubai (Arabic: برج دبي 'Dubai Tower') is a supertall skyscraper currently under construction in Dubai in the 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 2 km² (0.8 sq mi) development called 'Downtown Burj Dubai' and is located at the 'First Interchange' (aka 'Defence Roundabout') along Sheikh Zayed Road at Doha Street.
The tower's architect is Adrian Smith of Skidmore, Owings and Merrill, the architecture and engineering firm in charge of the project. The primary builder is Samsung, along with Besix and Arabtec. Third party peer review has been performed by CBM Engineers.
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.
As of 27 December 2007, Burj Dubai has reached a height of 598.5 m (1,964 ft), with 158 completed floors.
Burj Dubai's last two milestones will be to surpass the 628.8 m (2,063 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 (646.4 m (2,121 ft) until it collapsed in 1991) to become the world's tallest structure of any type ever built.
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 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 700 m (2,297 ft), and it would be the world's tallest free-standing structure when completed.
Though unconfirmed, Burj Dubai has been rumoured to have undergone several 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 the height cannot be changed.
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 1,022 m (3,353 ft) in height with 200 floors.
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.
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 50 km (31 mi) from the Burj Dubai site. Speculation has suggested various heights between 700 m (2,297 ft) and 1,200 m (3,937 ft), but the developer is keeping the final height tightly under wraps.
The tower is being constructed by a South Korean company, Samsung Engineering & Construction which also built the Petronas Twin Towers and 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. Burj Dubai is expected to rise to 150% of the height of the Sears Tower. Emaar has also engaged GHD, 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 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 aluminium 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 440 metres (1,444 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 18 m/s (40 mph). The world's current fastest elevator (in the Taipei 101) travels at 16.83 m/s (37.6 mph). 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 carry 42 people at a time.
Engineers rotated the building 120 degrees from its original layout to reduce stress from prevailing winds. Over 45,000 m³ (58,900 cu yd) of concrete, weighing more than 110,000 metric tons (121,000 S/T/108,000 L/T) were used to construct the concrete and steel foundation, which features 192 piles buried more than 50 m (164 ft) deep.
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. Burj Dubai will cost US$ 800 million to build and the entire 2 km² (0.77 sq mi) 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.
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 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 October 2, 2007 concrete was pumped to a delivery height of 588 m (1,929 ft).
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 that could withstand the thousands of tonnes bearing down on it, but also to 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.
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 (£4.34)/day, and laborers earn US$4.00 (£2.84). Unions were forbidden in the United Arab Emirates 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 (£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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