Steel framework goes up on the north side of the structure.
After a 27 year absence from collegiate turf, the University of Minnesota Gophers Big Ten football team opened its 2009 home schedule on Sept. 12 and returned to campus to a sold out and new, fan packed stadium.
Mortenson Construction, based in Minneapolis, Minn., along with dozens of sub-contractors delivered the new stadium to the University of Minnesota (U of M) and its football fans one month ahead of schedule and within budget.
The $288.5 million stadium is a structural steel skeleton with precast concrete risers for the stadium seating. With a “horseshoe style” design, the stadium features a 108 ft. (32 m) wide by 48 ft. (14 m) scoreboard and video screen at its open end and is one of the largest in college sports.
The open end faces southwest toward the U of M campus and downtown Minneapolis.
Stonemasons laid 760,000 bricks on the outdoor façade of the stadium walls to replicate the look of the team’s former, on campus home, Memorial Stadium.
Designers also provided for an expansion in seating capacity of 30,000 seats to bring total capacity to more than 80,000 fans.
Financing came from a combination of state funds, student fees and private donations, including a $35 million contribution from TCF Financial Corporation of Wayzata, Minn., for stadium naming rights.
After two years of construction and another year of removals and site preparation, the University of Minnesota Marching Band ushered in the return of outdoor football to the U of M campus and its legion of fans.
The sell out crowd of 50,805 enthusiastic football fans descended onto TCF Bank Stadium to be part of U of M campus history and watch their team beat the Air Force Academy 20 to 13 on a warm, Saturday evening just hundreds of feet from the site of the team’s original home.
Starved for some old fashion college football spirit, fans from across the state and the nation welcomed the Gophers home to a standing ovation when they ran onto the new field.
Signs of the past returned to the present to make the tradition of outdoor football complete. Along with the horseshoe shape and brick façade, players ran, tackled and tumbled outdoors on synthetic FieldTurf just as teams in the past had done for more than 60 years. And the U of M Marching Band of 200 plus brass and drum musicians played and sang the team’s theme song, the Minnesota Rouser.
The Minnesota Gophers moved off campus, to the dismay of team boosters and fans, to the indoor field and air supported dome of the Hubert Humphrey Metrodome in 1982 after Memorial Stadium began showing signs of severe wear and tear.
The Metrodome also became the home of the Minnesota Twins and Vikings that same year, who moved indoors to escape Minnesota’s somewhat fickle spring and summer climate and the snow and cold of late fall.
Since the controversial move, there was always talk of moving the Gophers back to campus.
According to the U of M Web site, discussions began carrying some serious weight in 2003 when university officials began seeking funds from the state and private donors to launch a new stadium, citing poor revenue and a lack of college atmosphere for moving the team back home.
It was not until the spring 2006 Minnesota legislative session, according to the Web site, that a final funding and construction bill for the new stadium was approved. This came after a variety of funding proposals and another joint U of M and Minnesota Vikings plan were proposed and vetoed down.
With the funding in-place, planning and design kicked into high gear. The University of Minnesota brought on Populous out of Kansas City, Mo., to design the new stadium.
Located in the northeast quadrant of the campus, the 26.9 acre (11 hectare) stadium site is part of a future expansion of 75 acres to the college. Along with the stadium, current plans call for the construction of an additional 10 new academic buildings by 2015.
On what was once a huge and long time parking lot, Veit from Rogers, Minn., moved onto the site in the fall of 2006 to begin site clearing and earth work. Operating a series of Cat dozers and backhoes, Veit crews installed much of the underground utilities, placed erosion control and removed hazardous materials.
During construction of the stadium, Veit workers also removed and recycled much of the construction waste.
Nearly at the same time, Frattlone Company, based in Little Canada, Minn., hit the site to remove a grain elevator complex that was more than 1,000 ft. (310 m) long and featured a couple of head houses, including one that rose 185 ft. (58 m) above ground.
Bringing the structure down with explosives was not an option because the University Magnetic Resonance Imaging Research facility was nearby. Researchers were concerned that explosives could cause vibrations that might compromise their research, according to Jim Wutzke, Frattalone project manager.
Grain tanks water proofed with asbestos added another wrinkle to the project, Wutzke noted. So, Frattalone crews relied on the old reliable boom and wrecking ball technique to bring the structure down.
“Our plan was to remove and dispose of the asbestos impacted structures, demolish the recyclable concrete structures and use that debris to create a pile for the 999 Amercian to sit on and access the 185 ft. head house,” Wutzke explained.
Frattalone also brought in another 999 American crane to help with the demolition and relied on Cat excavators and LaBounty pulverizors to recycle the reinforced steel and concrete.
“Over 54,000 tons of concrete was recovered and recycled and we recovered over 1,500 tons of reinforcing steel for recycle,” Wutzke noted.
Much of the crushed concrete was used under the new parking lot for stadium parking and to be part of the road base of a nearby arterial street under going reconstruction, Wutzke said.
By early fall of 2007, with most of the site work completed, Mortenson crews rolled in with a variety of cranes, dozers and backhoes to begin pile driving operations. Along with a couple of Link-Belt cranes, Mortenson relied on American cranes including a HC-110 and a HC-80 to drill the piles.
Mortenson cranes drilled 2,133 piles for a total of 82,075 ft. (26,000 m) or 15.5 mi. (25 km). According to Brian Boe, Mortenson project superintendent, pile driving continued through the winter and spring months of 2008.
Once workers completed the pile driving, activity at the site increased dramatically. Steel erection crews from Amerect moved onto the site and the stadium began rising from the ground and quickly took form during the spring and summer months of 2008.
Along with the steel crews, more than 60 sub-contractors and their workers moved in and out of the site, making construction phasing and coordination a critical piece of the project.
At any one time, there “were 600 workers on site with a peak of around 750 workers. Just managing the shear volume and moving six to seven hundred workers around the site at the same time is challenging,” said Joanna Slominski, the stadium construction manager of Mortenson.
To keep the work flowing and maintaining progress, Mortenson divided the construction of the stadium into three separate areas, Boe added.
“For the steel erection, each area of the stadium is divided by an expansion joint,” Boe explained. “We started on the north and south sides with all of our piles and structural steel.”
Working from both sides of the stadium, a combination of Grove, Link-Belt and Manitowoc cranes picked steel beams, some weighing 42,000 lbs. (14,500 kg) to waiting iron workers high above the ground.
Crews worked “from the west end and they worked east until they came to the end of the horseshoe and then they closed it off,” Boe said.
Once iron workers completed enough of the steel skeleton, crews began placing the pre-cast concrete risers for the stadium seating. At this stage, Mortenson relied on a newer and innovative method to fix the pre-cast to the steel.
“Basically, we used suction cups. The older method used hooks to set the pre-cast risers to the metal,” Boe explained. “Well, that causes damage to the precast. The method used on this stadium, which has been used in Europe for quite a few years, is to place the precast risers on ’suction cups’ operated by hydraulic suctioned air.”
It’s efficient, Boe said because “it speeds up time and the quality of work.”
Crews eventually placed 24,000 cu. yds. (18,000 cu m) of cast-in-place concrete and lifted into place 8,000 tons (7,200 t) of steel to complete the structural phase of the stadium.
Mortenson also relied on 3D modeling to visualize all the construction details and elements, Boe added.
“We modeled the entire stadium to show all the structural elements, the precast, the mechanical duct work, the large feeder conduits for electrical and the piping into a 3D model,” Boe said. “We put all these details into the model early on in construction when we were pounding piles.”
It was a lot of work at the front end because of the sheer quantity of data necessary, including dimensions and sizes of all the elements, yet very beneficial during construction, Boe emphasized.
“That way when we get to the point of installing all the internal elements like the duct work and the wiring, we know exactly where to put it,” or, as Boe succinctly remarked “if you don’t do that; you hurry up to get the building ready, you rough everything in on the ceiling, and then you put the ceiling in and nothing fits.”
Internal and behind the walls statistics drive home the validity of this 3D program. Inside the stadium and concealed behind its walls are 7500 light fixtures, 706,000 ft. (214,000 m) or 133 mi. (210 km) of electrical conduit, 2,210,000 ft. (625,000 m) or 418 mi. (650 km) of wire for power, 2,020,000 ft. (615,000 m) or 383 mi. (600 km) of cable for telecom, broadcast, fire and security systems and 33,000 ft. (1,000 m) of fiber optic cable with 900 terminations points.
Adding to this congested potpourri of wiring and cable are thousands of feet of plumbing and air and heating duct work behind the stadium walls.
With the stadium up and nearly completed in the spring of 2009, crews from FieldTurf moved in and installed 72,753 sq ft. (6,760 sq m) of synthetic turf.
Manufactured in Georgia, FieldTurf is designed to look and feel like natural grass and its fibers are soft and easy to slide on, according to company literature.
This is all placed on “three different layers of varying sizes of crushed granite spread out by small dozers and skidloaders attached with grade lasers to check grade,” Boe explained.
Once the turf is rolled out, it is filled in with recycled rubber and sand, Boe added.
Not only does FieldTurf save 2.5 to 3.5 million gal. (9.5 to 13.1 million L) of water each year, company documents further state their clients also save an estimated $30,000 to $60,000 a year in field maintenance costs.
Along these same lines of environmental savings, the new stadium relied on recycled material as well for many of the internal elements including doors and countertops while 97 percent of the steel skeleton came from recycled steel, Boe said.
Workers also recycled 97 percent of the construction waste including thousands of tons of concrete, metal, asphalt, wood, sheetrock and paper and cardboard products, Slominski noted.
Energy efficient lighting, water efficient plumbing fixtures, storm water quantity control and low VOC paint/carpet/adhesives for cleaner air quality further enhanced the environmental benefits and cost savings.
As a result of these efforts, project manager Slominski added that it is a green building that achieved LEED Silver, the first collegiate football stadium to earn this certification.
LEED is a third party validation process developed by the U.S. Green Building Council to show a building or community was designed and built with a positive environmental impact.
Utilizing recycled materials, recycling waste, energy savings and reduced carbon dioxide emissions are some of the parameters considered in the evaluation process.
Both Slominski and Boe are pleased with the project.
“It went really well. It was challenging because of its size. However, the way we phased this project out, we could work in different areas of the stadium at the same time setting steel and the pre-cast,’ Boe explained.
“We did better than our projected completion date by more than a month,” Slominski remarked. “So we were doing really well with our schedule and I think a majority of that was due to our sequencing.”
“It all boils down to work flow,” Boe added. “If you don’t have the proper work flow, you get into that issue where you need overtime to get it done. We were able to establish a decent work flow.” CEG