Steel Shots: It’s Up...It’s Good!

Levi’s Stadium incorporates 529 buckling restrained braces (BRBs), the first use of such a system in an NFL Stadium. (Photo: Magnusson Klemencic Associates)  

As of last month, the NFL’s newest stadium has its first Super Bowl under its belt. And like the two teams in that game (the Denver Broncos and the Carolina Panthers), the project team had to overcome some pretty big obstacles—in this case, a location with the highest seismicity of any NFL stadium and a construction schedule that was accelerated by one year with the project design already underway.

The new home of the San Francisco 49ers, Levi’s Stadium, located in Santa Clara, Calif., has a seating capacity of 68,500 but is expandable to 75,000 (and in fact has already exceeded the latter number by nearly 2,000 during a professional wrestling event last year). To best facilitate the delivery of this large and complex stadium with its aggressive construction schedule, the 49ers and the stadium owner, the Santa Clara Stadium Authority, opted for a new hybrid project delivery model dubbed “integrated bridging design-build” (IBDB). Levi’s is the first NFL stadium to use IBDB delivery, a highly collaborative and enhanced version of traditional bridging design-build. This approach was chosen in order to limit risk and eliminate potential owner, architect and contractor disputes and cost overruns common with stadium projects.

Levi’s is also the first NFL stadium to use a buckling restrained brace (BRB) system. Given the stadium’s location between the San Andreas and Calaveras/Hayward faults—the most earthquake-prone location of any NFL stadium—it was essential that the structure be seismically advanced. BRBs are high-performance steel brace elements designed to specifically absorb forces generated during an earthquake—and the buckling restrained braced frames (BRBFs) used here are more efficient and provide higher capacity and greater architectural flexibility compared to conventional steel braced frames. The stadium incorporates 529 BRBs, ranging in capacity from 100 kips to 1,800 kips and are arranged in U-shaped “brace cores” around concessions and other areas.

For more about the design and construction of Levi’s Stadium, see the article “It’s Up...It’s Good!” in our current March issue (available now!).