The press box at the famed Rose Bowl, located in Pasadena, California, is currently being renovated and expanded. Luxury suites, club seats, lounge areas, and 1,900 premium seats are being added. Courtesy of the Rose Bowl Operating Company
Renovation work at the Rose Bowl—home of the UCLA Bruins and football’s famed New Year’s Day Rose Bowl playoff game—is nearing an end.
July 30, 2013—Expanding capacity at a beloved National Historic Landmark that is viewed by millions of people every year is tricky; even more so when the site is a stadium with an elliptical shape determined not only by necessity, but also by its historically protected design. Despite these challenges, the team conducting the renovation work at the Rose Bowl, in Pasadena, California, struck upon a solution that preserved the sight lines, look, and feel of the historic stadium while expanding the available space: they built out—and down. By demolishing and rebuilding the north and south wings of the press box, expanding its central wing, and adding an entirely new lower level to the concourse, the stadium was unobstrusively expanded to accommodate visitors and the press.
The original stadium was designed by local architect Myron Hunt in 1921; its field sits in an excavated bowl, the soil collected during the excavation used to create a berm that surrounds the field and supports the lower levels of stadium seating, according to Bruce Gibbons, P.E., S.E., LEED-AP, a managing principal of the Los Angeles office of Thornton Tomasetti and the firm’s project principal for the Rose Bowl expansion. At the rear of the existing bowl, the berm falls away and the seating steps are suspended from the stadium’s perimeter wall.
While the original stadium was designed as a horseshoe in plan, it was later enclosed to create its current elliptical shape; seats have been added and the stadium has been progressively modernized over the years, according to Gibbons.
The current $152-million construction project includes renovation and expansion work on the press box—located along the western side of the stadium, behind the upper tier of seats—to triple the press box in size and add luxury suites, club seats, and lounge areas, as well as 1,900 premium seats. The project also includes widening access tunnels, adding new pedestrian passageways under the bowl, and adding a variety of new service buildings and restrooms. “It became quite an intricate job to sequence,” Gibbons says. Because the stadium hosts the University of California Los Angeles’ football team, construction work was a multiyear effort that could only take place in football’s off-season and on dates in which the stadium was not in use for other planned events.
The existing press box was a steel framed structure built in 1960 and expanded in 1992, according to Stephan Eisenreich, P.E., LEED-AP, a vice president in the Los Angeles office of Thornton Tomasetti and the firm’s manager for the project.
The project has included widening and deepening the existing center wing of the press box with five levels of steel framing, and the demolition and reconstruction of the press box’s side wings. Both side wings were rebuilt with two lower levels in concrete and four upper levels in steel framing.
The project included the expansion of the existing center wing of
the press box and the demolition and reconstruction of the press
box’s side wings. Thornton Tomasetti, Inc.
The new steel framing for the center wing has been placed around the existing press box core to both widen and deepen it so that escalators could be added, Gibbons says. Within the existing structure, new special concentric braced frames and a horizontal beam frame system were introduced into the existing steel frame to bring the lateral system up to code, he says. Where the existing system “wasn’t overstressed,” Gibbons says, “we kept it. [But] if we found connections in the existing braced frame that were overstressed, then we just took the bracing out.” New slanting columns were added on the bowl side of the structure to avoid any loads being placed on existing foundations.
The upper levels of the north and south wings are steel framing systems that are stabilized by buckling restrained braced frames, according to Eisenreich. “The system was selected for its reliable seismic performance and appealing look [because] the structure of these wings will be exposed,” he says. The floor framing in the wings consists of steel beams supporting slab-on-metal deck and cantilevered steel raker beams that support the new precast concrete seating trays.
The lower two concrete levels of the new north and south wings work like bookends for the existing berm and bowl structure, Eisenreich says. “Two-way concrete slabs and special reinforced concrete shear walls transfer the superstructure loads down to [a] foundation mat,” he says, while a two-story tall concrete box serves as a retaining structure for the outer edge of the berm, which extends to 30 ft in height in this location. The shoring wall was necessary as a temporary measure to hold back the berm during construction, he says, but it was incorporated into the permanent structure “as a shear key for sliding resistance and tie-down for overturning resistance,” Eisenreich says.
If a mat foundation and shoring wall had not been used, substantial piles capped with grade beams would have been necessary for the press box’s side wings because the loose fill of the berm’s soil would have provided minimal lateral resistance, which is particularly important in this highly seismic region, Gibbons notes. Creating the earthworks necessary to get a rig to the correct location to place the piles would have also added a significant amount of time and money to the project.
The alternative foundation that was chosen uses smaller piles that are tied back, and enabled the construction team to excavate down to a level at which a mat foundation could be installed, which enabled an extra concourse level to be added as well, Gibbons notes. “This was, both for the time and for the pricing, the way to go,” he says.
This will be the fourth press box for the stadium; the ribbon cutting ceremony occurred earlier this summer and the stadium is expected to be fully complete by the 100th Rose Bowl game that will take place in January 2014.
The Somerville, Massachusetts-based architecture firm D’Agostino Izzo Quirk Architects and the San Fernando, California-based joint venture, Bernards-Barton Malow were also involved in the project.