"The green light towers with the rolled members are the main focal point," says Mark Fultz, general manager for Able Steel, which is supplying 1,802 tons of structural and 394 tons of miscellaneous steel. "It gives you that old ballpark feel."
In balancing the fan and player experience with a strict, voter-approved budget, both the Cubs and the city of Mesa had to focus on value engineering from the start.
"The one interesting feature we helped steer toward modifying was the main roof beams," Futz says. "The initial design called for a plate-girder type assembly, and we were able to change that to a wide-flange beam coming directly out of the middle. What we ended up doing was basically taking a pie section right out of the web and pulling the bottom flange up to give it the overall look that was the initial intent all along, through a plate girder."
Not only did that help material costs, it helped speed up construction, Futz says. And it looks better than the initial conceptual design, he says, because it keeps the materials consistent throughout the entire facility.
Suntec Concrete, which is supplying 13,500 cu yd of concrete, also helped manage costs by working closely with Populous to add exposed concrete finishes on the suite level as well as decorative saw patterns throughout the entire site.
"The saw pattern ties into the stairs, the dugouts, the exterior buildings, the landscape areas and so on," says Matt Rogers, Suntec's senior project manager. "It was a huge focal point for our team and, in the end, is one of the pieces that everybody is going to see."
Suntec's most daunting tasks were achieving the precision required for pouring the risers and staying on schedule. There are 9,000 fixed seats in the stadium, which features a playing field 16 ft below grade.
In the span of 12 weeks, Suntec's team poured 46 different sections of the seating risers. The sections were about 100 linear ft entailing four risers at a time, for a total of about 400 linear ft in each pour. All of the 16,900 linear feet of the 7-in. risers were "stripped and faced" by the finish division to ensure a quality vertical face for the seating to mount to. There were many days the team handled two pours, according to Rogers.
"What we did differently on this project is we formed up three to six risers at a time and we stripped and faced 100% of all the risers, "Rogers says. "What's critical about that is that the vertical face on the riser has to be very plumb, because all of the stadium seating mounts directly to the concrete. We virtually eliminated any patch material."
A critical part of Suntec's scope was to finish a tunnel that leads from the Cubs dugout to an elevator lobby. The elevator takes players directly from field level up to grade so that they can privately access the stadium as well as their stand-alone clubhouse and a 31,000-sq-ft batting tunnel building about 1,000 ft away.
The concourse-level slab on grade required 100,000 sq ft of concrete. The concourse allows fans to walk 360° around the inside of the stadium, thanks to a concourse-level bridge structure under which people and vehicles can access the playing surface from left field.
The left-field building encompasses three levels. The lower (field) level totals 17,000 sq ft and includes locker rooms for the visiting team and umpires, consisting of cast-in-place perimeter walls and a 10-in.-thick structural deck overhead. The concourse level houses the ballpark's main commissary, restrooms, retail and offices. The roof level features a 3,500-sq-ft party deck, including open space with some bleacher seating. It was designed to provide the aura of the rooftop seating areas that overlook left field at Wrigley Field in Chicago.