Burj Kalifa is known as Burj Dubai before its inauguration is a supertall skyscraper constructed in the Downtown Burj Dubai district of Dubai, United Arab Emirates, and is the tallest man-made structure ever built. Construction began on September 21st 2004, and the tower was offiially opened on January 4th 2010. The building is part of the 2 SQM development called "Downtown Burj Dubai" at the "First Interchange" along Sheikh Zayed Road at Financial Centre Road (previously known as Doha Street).The tower's architect is Adrian Smith who worked with Skidmore, Owings and Merrill (SOM) until 2006. The architecture and engineering firm SOM is in charge of the project. The primary builders are Samsung Engineering & Construction and Besix along with Arabtec. Turner Construction Company was chosen as the construction manager. Subsequently, in a surprise move at its opening ceremony, the tower was renamed Burj Khalifa, said to honour the UAE President Khalifa bin Zayed Al Nahyan for his crucial support to save the Dubai economy fro collapse after the financial crisis. After the opening due to low demand, around 825 out of 900 apartments were still empty.
The architecture features a triple-lobed footprint, an abstraction of the hemerocallis flower. The tower is composed of three elements arranged around a central core. The modular, Y-shaped structure, with setbacks along each of its three wings, provides an inherently stable configuration for the structure and provides good floor plates for residential. Twenty-six helical levels decrease the cross-section of the tower incrementally as it spirals skyward. The central core emerges at the top and culminates in a sculpted spire. A Y-shaped floor plan maximizes views of the Arabian Gulf. Viewed from the base or the air, Burj Dubai is evocative of the onion domes prevalent in Islamic Architecture. The Y-shaped plan is ideal for residential and hotel usage, with the wings allowing maximum outward views and inward natural light.
The structure is modular in nature with a central hexagonal shaft or core and three branches that spread out at 120 degrees from each other. Attached to these branches are wall-like columns at a 9-meter spacing that simply drop off as each leg sets back, avoiding complex and costly structural transfers. In addition to its aesthetic and functional advantages, the spiralling "Y" shaped plan was utilized to shape the structural core of Burj Khalifa. This design helps to reduce the wind forces on the tower, as well as to keep the structure simple and foster constructability. The structural system can be described as a "buttressed core", and consists of high-performance concrete wall construction. Each of the wings buttresses the others via a six-sided central core or hexagonal hub. This central core provides the torsional resistance of the structure, similar to a closed pipe or axle. Corridor walls extend from the central core to near the end of each wing, terminating in thickened hammer headwalls. These corridor walls and hammerhead walls behave similarly to the webs and flanges of a beam to resist the wind shears and moments. Perimeter columns and flat plate floor construction complete the system.At mechanical floors, outrigger walls are provided to link the perimeter columns to the interior wall system, allowing the perimeter columns to participate in the lateral load resistance of the structure; hence, all of the vertical concrete is utilized to support both gravity and lateral loads. The result is a tower that is extremely stiff laterally and torsionally. It is also a very efficient structure in that the gravity load resisting system has been utilized so as to maximize its use in resisting lateral loads. As the building spirals in height, the wings set back to provide many different floor plates. The setbacks are organized with the tower's grid, such that the building stepping is accomplished by aligning columns above with walls below to provide a smooth load path. As such, the tower does not contain any structural transfers. These setbacks also have the advantage of providing a different width to the tower for each differing floor plate. This stepping and shaping of the tower has the effect of "confusing the wind": Wind vortices never get organized over the height of the building because at each new tier the wind encounters a different building shape
Interesting Facts about the Burj Dubai
Although the building's shape resembles the bundled tube concept of the Willis Tower, it is structurally very different and is technically not a tube structure.The tower is situated on a man-made lake which is designed to wrap around the tower and to provide dramatic views of it.The elevators have the world's longest travel distance from lowest to highest stop.Hot air on the outside condenses due to the large cooling needs of the building. The condensation is collected and used to water the buildings flora and fauna. 20 Olympic-sized swimming pools per year of water.There are 1,210 fire extinguishers on the site.At the peak cooling times, the tower requires approximately 10,000 tons of cooling per hour.The amount of steel rebar used for the tower is 31,400 metric tons - laid end to end this would extend over a quarter of the way around the world.Over 330,000 cubic meters of concrete was used at the completion of the tower.Dubai has set a new world record for vertical concrete pumping for a building, by pumping to over 460 metres. The previous record was held by Taipei 101 for pumping concrete up to a height of 448 metres.Burj Dubai break the world record for altitude transportation of concreteThe total area of cladding used to cover the Burj Dubai is equivalent to 17 football fields.The concrete used for the Burj Dubai is equivalent to: a solid cube of concrete 61 metres on a side, a sidewalk 1,900 kilometres long, the weight of 100,000 elephants.The tower's peak electricity demand is estimated at 36mva, equivalent to roughly 360,000 100-watt light bulbs.