As if anyone at the College of Engineering needs reminding of what engineers can accomplish, along comes Larry Novak with a presentation on the Burj Khalifa, the world’s tallest building, an astonishment of glass and embossed stainless-steel soaring half-a-mile above the city of Dubai in the United Arab Emirates.
Novak, the chief structural engineer for the International Code Council and previously an associate partner with the Chicago firm Skidmore, Owings & Merrill, was lead structural engineer on the Burj project. As a vehicle for translating the awe of that tower – its 200 floors, its views of the Arabian Gulf, its Y-shaped structure that tapers into a 30-story spire so narrow only one person can fit at the top – his talk didn’t disappoint.
“Building is human nature,” said Novak as a series of images of the so-named vertical city appeared on a screen behind him. “What do we do when we get a set of blocks? We stack them, right? We want to build. We want to build tall.”
He paused in front a graphic showing the planet’s highest buildings throughout the decades, with a rising line underscoring their extreme heights. “The Singer Building in 1908, the Empire State Building in 1931, the Taipei 101 in 2004 … all these buildings had the unique title of being the world’s tallest at one point. See the linear growth? It’s literally right through the roof.
“Imagine if that line keeps trending up what you’ll be building when you’re my age.”
Novak’s lecture, “The Philosophy of Engineering for the Burj Khalifa,” was sponsored by the Department of Civil, Architectural, and Environmental Engineering (CAEE) under the guidance of Dr. Abieyuwa Aghayere. It is the latest example in CoE’s tradition of inviting professionals to present lectures that enthrall and educate the next generation of engineers.
In fact, Hill Conference Room was full to overflowing with students and faculty from throughout Drexel University’s campus. One faculty member from the College of Medicine even brought her ninth-grade son, who said he hopes to be an engineer one day.
Altogether, it was a festive event in celebration of what engineers do best: create stuff.
“I am extremely impressed and gratified with the outcome of Larry’s lecture, and the impact on the student attendees,” said Aghayere.
Novak opened with “a couple of facts to ponder,” not all of them engineering-oriented but nevertheless impressive and meant to convey the singularity of the tower. Like the fact that it takes three months for window cleaners to wash all the windows; like the fact that the Burj has the only six-star restaurant on the planet; that when it’s raining at ground level, it’s often sunny at the top; and that the units in the largely-residential tower were fully sold out in three nights during the opening phase in 2010.
“It was so busy that people were standing in line to buy them,” said Novak. “The guy at the front of the line sold his unit to the guy at the end of the line … and made a profit.”
While Novak used both humor and family images of his children building backyard models, the talk was essentially designed for engineers. Novak discussed wind engineering, structural design, engineering for seismic risk, vortex shedding, lightning risk, the damping system (which he illustrated with a short video of a small model in his yard topped with a tiny box of water), pumping concrete up 2,000 feet, and the seamless integration of all these systems that enabled the Burj to be built.
The economy, he said, also has a role to play in the construction of such buildings; no company, let alone the bank backing it up, wants to build during an economic downturn. He also noted that the codes used to guide construction are the same as those taught to engineering students in the US.
“So what makes a building like this possible? The three rules of structural engineering are: constructability, constructability, and constructability,” said Novak. “That’s the key – making it very constructable. If they’re not buildable they’re not economical, and people don’t want to build them. Architects can draw a lot of things, but if they’re not buildable they’re just drawings.”
The tower has three modular elements arranged around a Y-shaped central core, a triple-lobed footprint anchored by a mat of 12-foot thick solid concrete and 2M square feet of space underground. The groundwater in Dubai has three times the sulfates of seawater, so the Burj’s foundations are encased. Setbacks along each of its wings provide an inherently stable configuration along with an appealing floorplan for residents – at no point in their units are residents more than 30 feet from a window. As the tower rises, 26 “helical” levels decrease the cross-section.
“Whatever we did at level 10 is the same as at level 100 and 180. We just stopped building a wing. No column transfers, no delays in construction. We just stopped building. We just kept tapering until we ran out of building,” said Novak. “It’s the same vocabulary throughout the whole tower.”
CAEE senior Tali Herzfeld was one of 50 or so students who came to hear Novak’s lecture. She took notes earnestly and plans to look into the movement of super tall buildings with respect to wind direction during hurricane-force winds.
“There were just a ton of things I hadn’t considered in building design in general, let alone for tall buildings. Also, the lecture incorporated comedy in an educational way – I didn’t think that structural engineering could be funny. It was really just a useful way to learn,” said Herzfeld. “I’ve been writing things down that we have discussed in lectures, but I never really had an image to connect the words to. And then I saw the bathtub damping system that he constructed with his son in his yard.
“The incorporation of visuals really made things clear,” she added, “and, really, just the discussion of all the aspects of designing a building really integrated so much of what I’ve learned into one lecture.”