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The Sky Is Not the Limit
3 Nov, 2011 By: Heather LivingstonAdvances in BIM and software interoperability are helping propel a boom in supertall building construction.
Editor's note: This article was originally published in the Fall 2011 issue of Cadalyst magazine.
For more than 100 years, the world has been beguiled by the idea of constructing buildings that reach into the heavens. After Gustave Eiffel wowed the world in 1889 with his delicately latticed tower, humbled American architects began to embrace the idea of the tall building. Although the first skyscrapers were modest interpretations of the dream, they still were feats of engineering and architecture, and each time a skyscraper went up, technology evolved to make the dream possible.
During the 1920s and '30s, the skyscraper trend intensified into a national fervor in the United States, and the boom of construction gave rise to the Chrysler Building and Empire State Building in Manhattan. Of course, both were in high competition to claim the mantle of world's tallest — a title the Empire State Building won by 204 feet. The Skyscraper Museum in New York City considers that structure's 1,250-foot height to be the low bar for supertall skyscrapers today.
Current Quest
According to the Skyscraper Museum, in 2007 there existed 35 buildings — completed or on the boards — that fit the height requirement for categorization as supertall. Twelve of those projects dropped off the census as unrealized, but another 26 have been added for the current total of 49. 
"When the Twin Towers were destroyed in the terrorist attacks of 9/11, many predicted the end of the skyscraper era," says Carol Willis, director of the museum. "They were wrong. As [our] exhibition shows, supertalls are a significant building type of the 21st century."
The quest to construct the world's tallest building continues today. At present, the two-year-old Burj Khalifa (located in Dubai, United Arab Emirates, and previously known as the Burj Dubai) holds the title of world's tallest at 2,717 feet. Designed by Adrian Smith when he was at Skidmore, Owings & Merrill, the Burj Khalifa's record already has been challenged, and its fall to second tallest is imminent.
The challenger is the Kingdom Tower, now in design development by Adrian Smith + Gordon Gill Architects (AS+GG). To be located in Jeddah, Saudi Arabia, the structure is projected to reach a height of at least one kilometer, or 3,280 feet.
"Our vision for Kingdom Tower is one that represents the new spirit of Saudi Arabia," said Smith. "This tower symbolizes the Kingdom [of Saudi Arabia] as an important global business and cultural leader and demonstrates the strength and creative vision of its people. It represents new growth and highperformance technology fused into one powerful iconic form."
Indeed, that desire to provide structural evidence of one's arrival on the world scene — be it a corporation such as General Motors, an entrepreneur such as Donald Trump, or a country such as Saudi Arabia — has been the driver for many tall structures. It's what propelled Manhattan and Chicago to their storied heights, and it's what is driving the current proliferation of supertall structures in Asia and the Middle East.
Technology Sets the Pace
As was true in those early, heady days of the skyscraper, today's design and construction technologies continue to evolve, allowing these extraordinary structures to be not only conceived but also delivered. Robert Sinn is the leader of Thornton Tomasetti's Building Structure practice and is the engineering firm's principal-in-charge for the Kingdom Tower. Sinn identifies advances in construction technology such as high-strength concrete, super-fast elevators, and mass-tuned dampers as being key to the creation of supertall structures. He also credits increasingly effective wind tunnel studies and design analysis software that tap computational geometry.
Ken Murphy, Thornton Tomasetti's BIM (building information modeling) director, agrees that computational geometry is a boon to these massive projects because it provides mathematical computation capabilities rather than strictly design models. The computational geometry platforms enable designers and engineers to exploit the building information model for purposes that go beyond implementing simple design changes such as altering the number of floors or points of egress. Instead, embedded algorithms extend the changes to automatically adjust material quantities such as building skin elements and columns. "As we get further in the design process, we can do things such as panelization studies on a facade where a lot of mathematics tie into the model, and then we'll optimize for how many panels need to be a unique size or bent out of plane to avoid cost [overruns]."
Murphy added that this functionality is especially advantageous when competing for projects, because it allows users to generate multiple design iterations very quickly.
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About the Author: Heather Livingston
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