The new University of Phoenix Stadium has a "wow" factor that is going to be hard to beat for a very long time. It is the first stadium in the US to have both a retractable field and a retractable roof. Its 94,900 s.f. retractable natural grass field moves along at 11.5 feet per minute. The facility’s retractable roof is the first to have a system that stores energy during opening that is then used during closing the roof. If these features aren’t intriguing enough, the stadium’s 63,400 to 72,800 seating capacity, 88 luxury lofts, and high-resolution scoreboards should do the trick. With everything this high quality stadium has to offer, it is no wonder it was chosen by Business Week as one of The World’s Ten Most Impressive Sports Structures and by Popular Science as one of the 100 Best Innovations of 2006.
The $450 million University of Phoenix Stadium was designed from day one to set the standard for stadiums around the world, and it is proving to have done just that with its unique design and construction method. In just 36 months, and within the specified budget, the Arizona Cardinals can be proud to have a new stadium to call home.
Led by Hunt Construction Group, University of Phoenix Stadium was delivered using an innovative design-build system that paired designers and contractors on a daily basis to solve the many challenges of the unique stadium design. As conceived by Peter Eisenman of Eisenman Architects, the stadium was envisioned as a shimmering metallic barrel cactus planted on the desert landscape. Through pairing Eisenman’s design vision with the know-how of renowned sports architects HOK Sport, the teams of engineers and specialty subcontractors assembled by Hunt collaborated to quickly work out the key aspects of the stadium’s design and construction.
University of Phoenix Stadium is a testament to the many benefits of the design-build construction method. By using design-build and creating open lines of communication throughout the project, Hunt was able to realize cost savings which translated into the ability to add scope to the building and reduce the overall project budget. Project Executive, Robert S. Aylesworth Jr. added, "[University of Phoenix Stadium] is proof that you can bring together high design, sports architecture, an aggressive budget, and dual ownership, put it all in one place, and we can deliver — on time and on budget."
Perhaps the most important aspect of the design-build method was allowing the owner and architects to explore new possibilities and take a bolder approach to design and construction elements. Aylesworth added, "We really have had the good fortune of participating in a project that is almost visionary." By pairing designers and specialty subcontractors at a scale unprecedented in the sports construction industry, the design-build approach employed at University of Phoenix Stadium dispels the myth that high design means high cost.
The innovative roof structure of University of Phoenix Stadium serves as a prime example of the collaborative spirit made possible by the design-build method. Throughout the design process, engineers at Walter P Moore worked side-by-side with fabricators and erectors at Schuff Steel to develop efficient structural, fabrication, and erection concepts. Extensive review and iteration of literally thousands of steel details early in the design process created a structural steel roof in which every piece fit perfectly into the fabrication fixtures and erection methods employed by Schuff.
At an efficient 32 psf of structural steel framing, the 490,000 s.f. long-span roof incorporates several innovative structural elements. Primary roof support is provided by two 700-foot-span Brunel trusses that run parallel to the field sidelines to supports on four massive concrete supercolumns at the corners of the stadium. The trusses are named after the engineer I.K. Brunel in deference to their similarity to the lenticular trusses that form the Royal Albert Bridge. Varying from 87 feet deep at midspan to a massive 15-foot-deep weldment at the end bearings, each Brunel truss directly supports a rail along which two 180-foot-long by 257-foot-span retractable panels bi-part.
Because of the sloping top chord of the Brunel truss, the retractable panels must operate along a curved slope. An innovative cable drive developed by Uni-Systems, Inc., working with Walter P Moore, provided an economical solution. Functioning much like a simple yo-yo, four cable drums are mounted on each moving panel with cables anchored to the Brunel truss at the peak of the roof. To open the roof, the cable drums simply allow the cable to slowly unwind, using the weight of the roof as energy to roll the structure slowly downhill. To close the roof, the cable drums wind themselves back up using several small horsepower electric motors. Redundant braking systems and electronic roof position monitoring keep all roof movements under strict control.
Erecting such a large roof structure hundreds of feet above the floor of the stadium is a fundamental challenge. In an effort to speed the erection process and enhance safety by keeping iron workers closer to the ground, Schuff Steel made a bold decision early in the process to build both Brunel trusses and the framing between them, including the retractable panels, on the ground. This entire 11.2-million pound assembly was then lifted to its final position atop four concrete supercolumns over the course of three days in an operation dubbed the "Superlift." Utilizing strand jacks and specialized computer control equipment from heavy-lift specialist Mammoet, the Superlift was successfully completed in February 2005 and stands as the world’s largest roof lift.
Due to the sequence in which various members of the roof were connected to accommodate this operation, accounting for the Superflift in the design and detailing of the roof structure drove the engineering process for Walter P Moore. Had such an erection process been proposed after issuing bid documents, it would have been ruled out as impossible due to fundamental changes necessary in the design. Instead, the design-build process allowed engineers and erectors to work together early in the design process to incorporate a superior construction method that brought value to the owner, erector, and construction manager.
In addition to accounting for the roof lift in design, Schuff Steel and Hunt Construction conducted an extensive operational planning exercise. Each action that was to occur during the lift process was carefully documented in a detailed roof lift manual that was used to train all personnel that would be present on site during the lift. Included in the lift manual were predetermined actions to address a complex series of "what-if" scenarios.
Another signature element of the stadium is the natural grass field that is designed to move in or out of the stadium. Even more impressive, the field completes this move in just over an hour. It represents the first completely retractable field ever constructed in the United States and one of only four in the world. With a roof opening optimized for fan comfort and economy of roof construction, the retractable roof does not provide enough light to grow grass indoors. The movable field was a natural solution to provide a superior playing surface on a site that has ample space to park the field in the warm desert sunlight outside the stadium. The retractable field means the multi-purpose facility can easily accommodate NCAA Final Four basketball, trade shows, conventions, concerts, motor sports, rodeos and more with a very short conversion time. Comparable facilities with palletized fields can take several days to be ready for trade events after a game.
Engineers at Uni-Systems and Walter P Moore developed a simple, practical, and reliable system to move the field tray out of the stadium. Riding on 13 1,150-foot-long lines of steel rail embedded in the event slab, the 234-foot by 403-foot steel framed tray sits on 542 boxes housing steel wheels. Each line of wheels along the outside of the tray is driven by a 1-hp motor.
The travel of the field tray is guided through the central rail. The actual playing surface consists of one foot of soil and sod over a drainage mat, all of which rest on a composite concrete slab. The stiffness of the supporting structure was precisely tuned through extensive testing of mock-ups in a first-of-its-kind study to create a playing surface that was rigid enough to avoid annoying vibrations yet had sufficient give to avoid injury. The resulting surface has earned high praise from NFL players.
Inside the stadium, fans can enjoy the beautiful architecture and innovative design that helps create excellent sight lines, comfortable seats, well-placed and abundant restrooms, plentiful concession stands, and an unobstructed view of the field from both the lower and upper concourse areas. The stadium can seat approximately 63,400 visitors for normal events and is expandable to 72,800 for special events such as the Super Bowl, NCAA Final Four, Fiesta Bowl, concerts, or any event requiring extra seating. The stadium also features 88 luxury lofts — known elsewhere as suites — that are unlike any in the industry. They include special parking, an exclusive entrance, private restrooms, multiple televisions, and in-loft catering. There is also a luxurious club level complete with wide seats, preferred parking, private entrances, and a club lounge.
Perhaps one of the most welcomed features for locals and travelers alike is the addition of Sportsman’s Park. The 160-acre area includes over 20 acres of turf, an eight-acre public area called the Great Lawn, and on-site car parks handling over 14,000 vehicles. This beautifully landscaped area will allow fans to enjoy the stadium year-round. It will also create the perfect tailgating atmosphere as fans can now picnic in the company of natural grass and trees instead of concrete and automobile fumes. The park will also feature a wide variety of vegetation selected to incorporate the farming heritage of the West Valley. To bring Sportsman’s Park to life, the Cardinals teamed up with award-winning architect Michael Dollin of Urban Earth Design. The goal was to create a design that would enhance game day for fans as well as serve as a park for the community throughout the year.
The stadium has already achieved icon status and has caught the eye of college football officials, who have scheduled back-to-back major bowls. Fans recently enjoyed the Tostitos Fiesta Bowl followed by the Bowl Championship Series title game within a week’s time in January. Super Bowl XLII is also scheduled for February 2008 and fans will surely hope to see the Cardinals play to the win in their own stadium when that time comes. Ted Ferris, Arizona Sports and Tourism Authority president, believes interest in the stadium is enormous and that it will be the busiest NFL stadium in the country. Realizing that goal will make the stadium a major economic engine for the Valley of the Sun.
The Cardinals held their first preseason game against the Pittsburgh Steelers on August 12, 2006 with a winning finish helping to prove the opening of University of Phoenix Stadium is a milestone for a rising-star NFL team. The Cardinals, their fans, and residents are proud to have such an impressive new facility. The team sold out all their season tickets, approximately 57,000 in all, for the first time since the team moved to Arizona.
Not only is the stadium a new landmark for the local community, it will also bring businesses and visitors to a fast growing area. "It impacted large businesses, small businesses, and minority- and women-owned businesses. Labor participated and had a lot of great new jobs and job training opportunities as well," says Michael Bidwill, vice president and general counsel for the Arizona Cardinals. "This really turned out to be a great win in terms of construction."
INFO: Walter P Moore (www.walterpmoore.com)