Category: Science & Technology
Key figures: Adrian Smith (design architect, Skidmore, Owings & Merrill), Bill Baker (structural engineer, Skidmore, Owings & Merrill), Mohamed Alabbar (chairman, Emaar Properties), Sheikh Mohammed bin Rashid Al Maktoum (Ruler of Dubai), Sheikh Khalifa bin Zayed Al Nahyan (President of the United Arab Emirates and namesake)
Summary
On 4 January 2010 the Burj Khalifa was officially inaugurated in Dubai, United Arab Emirates, becoming the tallest building and the tallest free-standing structure in the world. Rising to an architectural height of 828 metres (2,717 feet) across 163 floors above ground, the tower surpassed the previous record holders — Taipei 101 (509 metres) for tallest building and the CN Tower (553 metres) for tallest free-standing structure — by margins large enough to redefine the upper limit of what skyscraper construction was thought capable of achieving. Designed by the Chicago office of Skidmore, Owings & Merrill (SOM) and developed by the Dubai firm Emaar Properties, the building had taken roughly six years to construct, after ground was broken in January 2004.
The opening ceremony, attended by some 6,000 guests and marked by an elaborate fireworks and light display, coincided with the fourth anniversary of Sheikh Mohammed bin Rashid Al Maktoum’s accession as Ruler of Dubai. In a surprise announced at the inauguration, the tower — known throughout its construction as “Burj Dubai” — was renamed “Burj Khalifa” in honour of Sheikh Khalifa bin Zayed Al Nahyan, the President of the UAE and ruler of Abu Dhabi, whose emirate had provided emergency financial support to debt-stricken Dubai during the 2009 global financial crisis.
Design and engineering
The Burj Khalifa’s height was made possible by a structural innovation that SOM engineer Bill Baker termed the “buttressed core.” A central hexagonal reinforced-concrete core is braced by three wings arranged in a Y-shaped plan, each wing buttressing the others against wind and gravity loads while the tapering, stepped setbacks of the tower’s profile disrupt the formation of organised wind vortices that would otherwise cause dangerous oscillation at such heights. The Y-shaped footprint, inspired in part by the geometry of the regional desert flower Hymenocallis, also maximised the perimeter available for residential and hotel windows.
The design architect was Adrian Smith of SOM, working with Emaar Properties under chairman Mohamed Alabbar. The tower houses a mixture of uses — corporate offices, residential apartments, the Armani Hotel occupying the lower floors, and public observation decks, including the “At the Top” deck on the 124th floor, which opened to visitors on 5 January 2010.
Construction
Construction began on 6 January 2004 and the exterior structure was completed in 2009. The project consumed approximately 330,000 cubic metres of concrete and 55,000 tonnes of steel reinforcing bar, and required an estimated 22 million man-hours of labour. At the peak of construction the site employed thousands of workers — drawn predominantly from South Asia — and the building’s rapid vertical progress, using high-pressure concrete pumping to unprecedented heights, became a closely studied feat of construction logistics. The principal contractor was a joint venture led by South Korea’s Samsung C&T, with Belgium’s BESIX and the UAE’s Arabtec. The reported project cost was on the order of US$1.5 billion.
The renaming and Dubai’s debt
The tower’s last-minute renaming reflected the financial turmoil surrounding its completion. Dubai’s property and credit boom had collapsed during the 2008–2009 global financial crisis, leaving the emirate’s flagship state-linked conglomerate, Dubai World, unable to meet its debts. Neighbouring Abu Dhabi, the UAE’s oil-rich capital emirate led by Sheikh Khalifa bin Zayed Al Nahyan, extended a multi-billion-dollar rescue to Dubai. Naming the world’s tallest building after the UAE president was widely interpreted as an acknowledgement of that support, binding the tower’s symbolism to the wider story of post-2008 sovereign and corporate debt.
Records
At its opening the Burj Khalifa held a series of superlatives recognised by the Council on Tall Buildings and Urban Habitat and by Guinness World Records, including: tallest building in the world; tallest free-standing structure; greatest number of floors; highest occupied floor; and the longest single-running elevator travel distance. Many of these records, including tallest building in the world, the tower retained for more than a decade after its inauguration.
Significance
The Burj Khalifa marked a turning point in tall-building engineering, demonstrating that reinforced-concrete construction and the buttressed-core system could carry occupied space far beyond the limits of earlier steel-framed skyscrapers. It cemented Dubai’s strategy of using landmark architecture to project a global identity and to anchor tourism and real-estate development, even as the tower opened amid the very debt crisis that had nearly halted it. As the centrepiece of the surrounding Downtown Dubai development, it became one of the most recognised buildings in the world and the benchmark against which a subsequent generation of “supertall” and “megatall” towers would be measured.
Sources
- Wikipedia: Burj Khalifa
- Guinness World Records: Burj Khalifa — tallest building in the world
- Britannica: Burj Khalifa
- Gulf News: Burj Khalifa anniversary — inside the world’s tallest skyscraper