Burj Dubai
Burj Dubai 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. 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 who worked with Skidmore, Owings and Merrill (SOM) until 2006. SOM is the architecture and engineering firm in charge of the project. The primary builder is Samsung Engineering & Construction, 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.
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.
The tower is being constructed by a South Korean company, Samsung Engineering & Construction 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 , 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.[20] 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 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. The concrete pumps, pipelines and booms are provided by Putzmeister AG, of Aichtal, Germany.
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.
