Austin’s Circuit of the Americas gets an iconic observation tower using 350 tons of steel.
The Circuit of the Americas (COTA) in Austin, Texas, will host the United States Grand Prix from 2012 to 2021. While German Formula 1 specialist Hermann Tilke designed the racecourse and technical facilities, COTA’s owners hired local firm Miró Rivera Architects to turn out a main grandstand and amenities for the 9,000 fans expected to attend the races. In addition to imbuing the project with a variety of programmatic functions that go beyond racing, Miró Rivera created a sleek observation tower that gives spectators unrestricted views across the racetrack’s twisting expanse.
“Our idea for the tower was to be able to go way up and see the track from one focal point in a structure that was an iconographic symbol for the track,” said Miguel Rivera, founder and principal of the architecture firm. “Our inspiration came from Formula 1 cars, where speed and efficiency are so important.” Just like the track’s feature attractions, the tower’s design didn’t feature any excesses. Structural engineers at Walter P Moore helped ensure every piece of steel did some kind of work so the tower was as efficient as possible.
Working with the architects’ 2D drawings, the structural engineering team developed a three dimensional tower with all the requisite details for construction—right down to bolts and welding points—in Tekla Structures. “Everything that goes into fabrication is digitally defined in this program,” said Mark Waggoner, principal with Walter P Moore. “Generally, in our business, we deliver paper drawings for the steel fabricator to interpret and build, but we were able to bypass this step and print shop drawings directly from our model.” To increase efficacy, the engineers wrote some of their own connections for programming interfaces with steel fabricator Patriot Erectors.
Waggoner also located the joints, especially for the veil, (the tubular red feature, inspired by the tracers of a car’s tail lights in the dark) in Tekla. To reduce the cost of bending each 8-inch steel tube to the architect’s initial drawings, the program helped break large radii into segmented, straight lines to achieve time and cost savings. To facilitate shipment to the COTA track, the 20- by 20- by 250-foot structure was broken into four pieces that could be stitched back together on site. Patriot Erectors welded 10- by 10- by 30-foot sections in their Dripping Springs, Texas-facility that were assembled on three different casting beds and craned into position.
Reflecting on the 11-month digital design/build schedule, Waggoner said the process for the COTA Observation Tower was somewhat unconventional. “People generally like to have paper drawings for these types of projects,” he explained. “But at the end of the day, the general contractor felt this process saved us about three months of time.”