Burj Khalifa (Arabic: برج خليفة‎, "Khalifa Tower"), known as Burj Dubai prior to its inauguration, is a skyscraper in Dubai, United Arab Emirates, and is the tallest man-made structure in the world, at 829.8 m (2,722 ft).[3][8]

Construction began on 21 September 2004, with the exterior of the structure completed on 1 October 2009. The building officially opened on 4 January 2010,[1][9] and is part of the new 2 km2 (490-acre) development called Downtown Dubai at the 'First Interchange' along Sheikh Zayed Road, near Dubai's main business district. The tower's architecture and engineering were performed by Skidmore, Owings and Merrill of Chicago, with Adrian Smith as chief architect, and Bill Baker as chief structural engineer.[10][11] The primary contractor was Samsung C&T of South Korea.[12]

Conception

Burj Khalifa was designed to be the centerpiece of a large-scale, mixed-use development that would include 30,000 homes, nine hotels (including The Address Downtown Dubai), 3 hectares (7.4 acres) of parkland, at least 19 residential towers, the Dubai Mall, and the 12-hectare (30-acre) man-made Burj Khalifa Lake.

The decision to build Burj Khalifa is reportedly based on the government's decision to diversify from an oil based economy to one that is service and tourism based. According to officials, it is necessary for projects like Burj Khalifa 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.[13]

Height

Records

Tallest existing structure: 829.8 m (2,722 ft) (previously KVLY-TV mast – 628.8 m or 2,063 ft)

Tallest structure ever built: 829.8 m (2,722 ft) (previously Warsaw radio mast – 646.38 m or 2,121 ft)

Tallest freestanding structure: 829.8 m (2,722 ft) (previously CN Tower – 553.3 m or 1,815 ft)

Tallest skyscraper (to top of spire): 829.8 m (2,722 ft) (previously Taipei 101 – 509.2 m or 1,671 ft)

Tallest skyscraper to top of antenna: 829.8 m (2,722 ft) (previously the Willis (formerly Sears) Tower – 527 m or 1,729 ft)

Building with most floors: 163 (previously World Trade Center – 110)[14]

Building with world's highest occupied floor: 584.5 m (1,918 ft)[15][16]

World's highest elevator installation (situated inside a rod at the very top of the building)[17]

World's longest travel distance elevators: 504m (1,654 ft)[17][18][dead link]

Highest vertical concrete pumping (for a building): 606 m (1,988 ft)[19]

World's tallest structure that includes residential space[20]

World's second highest outdoor observation deck: 124th floor at 452 m (1,483 ft)[21][22] When it first opened, the observation deck was the highest outdoor observation deck in the World, but it has since been surpassed by Cloud Top 488 on top of Canton Tower.[23]

World's highest installation of an aluminium and glass façade: 512 m (1,680 ft)[24]

World's highest nightclub: 144th floor[25]

World's highest restaurant (At.mosphere): 122nd floor at 442 m (1,450 ft) (previously 360, at a height of 350 m (1,148 ft) in CN Tower)[26][27]

World's highest New Year display of fireworks.[28]

World's second highest swimming pool: 76th floor[29] (world's highest swimming pool is located on 118th floor of Ritz-Carlton Hotel at International Commerce Centre, Hong Kong).

History of height increases

Burj Khalifa compared with some other well-known tall structures

There are unconfirmed reports of 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 by Skidmore, Owings and Merrill (SOM).[30] Marshall Strabala, an SOM architect who worked on the project until 2006, in late 2008 said that Burj Khalifa was designed to be 808 m (2,651 ft) tall.[31]

The design architect, Adrian Smith, felt that the uppermost 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 current height.[citation needed] 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.[32]

Delay

Emaar Properties announced on 9 June 2008 that construction of Burj Khalifa was delayed by upgraded finishes and would be completed only in September 2009.[33] 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."[34] A revised completion date of 2 December 2009 was then announced.[35] However, Burj Khalifa was opened on 4 January 2010, more than a month later.[1][9]

Features

The Dubai Fountain

The Dubai Fountain

Main article: The Dubai Fountain

Outside, WET Enterprises designed a fountain system at a cost of Dh 800 million (US$217 million). Illuminated by 6,600 lights and 50 coloured projectors, it is 275 m (902 ft) long and shoots water 150 m (490 ft) into the air, accompanied by a range of classical to contemporary Arabic and world music.[65] On 26 October 2008, Emaar announced that based on results of a naming contest the fountain would be called the Dubai Fountain.[66]

View from the observation deck looking north

Observation deck[e

View from the observation deck

An outdoor observation deck, named At the Top, opened on 5 January 2010 on the 124th floor.[67] It is the third-highest observation deck in the world and the second-highest outdoor observation deck in the world, at 452 m (1,483 ft).[23] The observation deck also features the Behold Telescope, an augmented reality device developed by gsmprjct° of Montréal, which allows visitors to view the surrounding landscape in real-time, and to view previously saved images such as those taken at different times of day or under different weather conditions.[68][69] To manage the daily rush of sightseers, visitors are able to purchase tickets in advance for a specific date and time and at a 75% discount over tickets purchased on the spot.[70]

On 8 February 2010, the observation deck was closed to the public after power-supply problems caused an elevator to become stuck between floors, trapping a group of tourists for 45 minutes.[71][72] Despite rumours of the observation deck reopening for St. Valentine's Day (14 February),[73] it remained closed until 4 April 2010.[74][75][76]

Burj Khalifa park

Burj Khalifa is surrounded by an 11 ha (27-acre) park designed by landscape architects SWA Group.[77] The design of the park is also inspired by the core design concepts of Burj Khalifa which is based on the symmetries of the desert flower, Hymenocallis.[78] The park has six water features, gardens, palm lined walkways, and flowering trees.[79] At the centre of the park and the base of Burj Khalifa is the water room, which is a series of pools and water jet fountains. In addition the railing, benches and signs incorporate images of Burj Khalifa and the Hymenocallis flower.

The plants and the shrubbery will be watered by the buildings's condensation collection system that uses water from the cooling system. The system will provide 68,000,000 L (15,000,000 imp gal) annually.[79] WET Enterprises, who also developed the Dubai Fountain, developed the park's six water features.[80]

Source : http://en.wikipedia.org/wiki/Burj_Khalifa