Red Hawk
JUST WIN!
Football palace rises one concrete slice at a time
Tom Tingle/The Arizona Republic
Pat Flannery
The Arizona Republic
Apr. 11, 2004 12:00 AM
Drivers cruising Loop 101 through Glendale have probably noticed it: the jagged concrete creature clawing its way out of the ground just south of Glendale Arena.
It is hardly a vision of the futuristic football palace it will become in two years, particularly because it doesn't yet have its distinctive oval shape. There's a reason the Arizona Cardinals' next home still doesn't have a familiar look.
The stadium is going up in an unconventional way to make construction more economical and efficient, and it will give builders more time to finish off the inside of the publicly subsidized facility before it opens for the 2006 National Football League season.
Instead of building Cardinals Stadium in circles, one layer at a time like a layer cake, the stadium is being built in sections, somewhat like making a pie slice by slice. Sections are being erected one at a time, from the field level to the upper concourse, starting in the stadium's northeastern corner. Those in the northern half of the stadium are targeted for completion by mid-August, and those in the southern half are targeted for completion by Dec. 15.
Related
• More on the Cardinals Stadium »
What puzzled motorists now see as they breeze by the site are the northern sections taking shape, with parts climbing all the way to the upper-concourse level.
This isn't the first time a stadium has been built this way, but it is a less traditional method. Builders thought it made sense not only because it saves time, but because it solves logistical problems involving the use of heavy machinery, and it makes roof construction safer for steel workers.
"It's a three-year job no matter which way you do it, but in terms of work sequencing, . . . this made a lot more sense," said Kenny Harris, the state Tourism and Sports Authority's vice president of facilities.
BUDGETARY CONCERNS
Cost-efficiency is vital to the project, whose cost ballooned from $331 million two years ago to the current $370.6 million. Much of that increase is attributable to delays in finding a home for the stadium, and the Cardinals are supposed to pick up the extra cost.
Already, certain interior features that would make the stadium more appealing as a convention facility have been scrapped by the state Tourism and Sports Authority to keep costs in check. It will still be a multipurpose facility, but items such as field-level meeting rooms were crossed off the list of amenities. A private firm selected to manage the stadium has agreed to spend $500,0000 to develop some of those missing features.
In documents signed late last year, Hunt Construction Group guaranteed not to exceed the current cost and to finish by summer 2006.
"I know they have made the decision that this approach gives them the best chances of being done in time and on budget," the authority's president, Ted Ferris, said of the building scheme.
Finishing on time and on budget is no small task, particularly given the complexity of certain elements of the job, like building the roof or the massive moving tray that will allow the entire turf field to roll out. An array of machines and concrete forms are needed at different times for different tasks, so scheduling construction to keep the various mechanical monsters out of one another's way was vital. Otherwise, the construction site would take on the look and efficiency of a game of Twister.
A CHALLENGING JOB
One of the project's masterminds, Hunt construction manager Charlie Prewitt, said the project presented several vexing issues. First, he wanted to give workers plenty of time to finish interior work, from locker rooms and seats to luxury boxes and concession stands, with a roof overhead.
But the toughest problem was figuring out when, where and how to build the stadium's two enormous Brunel roof trusses, named for the engineer who devised their particular style for an English railroad bridge in the mid-19th century. When fully assembled, each of the giant trusses will be as long as three Boeing 747 jets placed end to end, as tall in the middle as six London double-decker buses and weigh as much as 400 fully-loaded Hummers.
The trusses will bear most of the weight of the stadium's roof, whose retractable panels will slide open atop the trusses. The trusses and panels together will weigh as much as a small ship. Smaller roof-support structures eventually will connect to the Brunel trusses.
Prewitt wanted a way to start building them sooner, allowing the roof to go up earlier.
Another challenge was how to most efficiently use the concrete forms that shape the stadium's structure, and how to use the giant crane that hoists those forms into place. That crane and several smaller ones are positioned inside and outside the bowl to build the structure. Eventually, they must be moved to make way for other equipment.
THINKING VERTICALLY
Each section has uniquely shaped concrete forms used to build the structure. First, support columns are poured. Then a 2-foot-thick slab full of wafflelike indentations is poured atop the columns to make the next floor. Then another set of columns. Then another slab. So it goes until workers reach the top level of the structure. Starting times for each section are staggered.
Building sections in this manner allows concrete forms to be immediately reused by slipping them out from under one slab floor with a crane and raising them up to pour the same section's next level. In a circular construction routine, work would jump from one section to the next at the same level, requiring constant changes in concrete forms.
This efficiency also allows the giant crane to stay in one area at a time, rather than circling the stadium.
When the northern and eastern sections of the stadium are finished, a milestone expected in August, the same forms will be used in a similar order on the southern and western sides.
Had the circular method been used, assembly of the roof trusses could not have begun until the entire stadium frame was finished. At that point, workers would have begun to build the trusses high above the stadium floor, with shoring beneath to support them.
Truss assembly will start on the stadium floor when the northern half of the structure is done. The trusses will be raised into place upon completion.
"This makes it safer. They are not working 200 feet in the air . . . which makes it a lot easier to do," construction manager Charlie Prewitt said.
RAISING THE ROOF
Assembly of the northern halves of the trusses will start on the ground inside the stadium as soon as the northern concrete work is finished. All of the equipment used to build the concrete frame at the northern end will shift to the southern end, making room for equipment needed to build the trusses at the northern end.
"The good thing you get out of this is you can start building trusses about three months earlier," construction manager Charlie Prewitt said. "That means you get the roof on three months earlier, which gives you about three months extra to do interior work."
When constructing the trusses, the mazes of steel beams will be assembled on the ground. Their northern ends will be placed in special concrete channels, allowing them to be lifted onto the stadium's supercolumns, four oversize concrete pillars that will support the full weight of the retractable roof.
As the southern concrete structure is being finished, making the bowl complete, work starts on the southern halves of the trusses. The roof panels will be attached, and the entire contraption will be slowly jacked into position atop the supercolumns in February.
Once the trusses and roof panels are atop the supercolumns, builders can put the "lid" on the stadium. From there, it's simply a matter of adding the final ingredients: a finished interior and the movable field.
Tom Tingle/The Arizona Republic
Pat Flannery
The Arizona Republic
Apr. 11, 2004 12:00 AM
Drivers cruising Loop 101 through Glendale have probably noticed it: the jagged concrete creature clawing its way out of the ground just south of Glendale Arena.
It is hardly a vision of the futuristic football palace it will become in two years, particularly because it doesn't yet have its distinctive oval shape. There's a reason the Arizona Cardinals' next home still doesn't have a familiar look.
The stadium is going up in an unconventional way to make construction more economical and efficient, and it will give builders more time to finish off the inside of the publicly subsidized facility before it opens for the 2006 National Football League season.
Instead of building Cardinals Stadium in circles, one layer at a time like a layer cake, the stadium is being built in sections, somewhat like making a pie slice by slice. Sections are being erected one at a time, from the field level to the upper concourse, starting in the stadium's northeastern corner. Those in the northern half of the stadium are targeted for completion by mid-August, and those in the southern half are targeted for completion by Dec. 15.
Related
• More on the Cardinals Stadium »
What puzzled motorists now see as they breeze by the site are the northern sections taking shape, with parts climbing all the way to the upper-concourse level.
This isn't the first time a stadium has been built this way, but it is a less traditional method. Builders thought it made sense not only because it saves time, but because it solves logistical problems involving the use of heavy machinery, and it makes roof construction safer for steel workers.
"It's a three-year job no matter which way you do it, but in terms of work sequencing, . . . this made a lot more sense," said Kenny Harris, the state Tourism and Sports Authority's vice president of facilities.
BUDGETARY CONCERNS
Cost-efficiency is vital to the project, whose cost ballooned from $331 million two years ago to the current $370.6 million. Much of that increase is attributable to delays in finding a home for the stadium, and the Cardinals are supposed to pick up the extra cost.
Already, certain interior features that would make the stadium more appealing as a convention facility have been scrapped by the state Tourism and Sports Authority to keep costs in check. It will still be a multipurpose facility, but items such as field-level meeting rooms were crossed off the list of amenities. A private firm selected to manage the stadium has agreed to spend $500,0000 to develop some of those missing features.
In documents signed late last year, Hunt Construction Group guaranteed not to exceed the current cost and to finish by summer 2006.
"I know they have made the decision that this approach gives them the best chances of being done in time and on budget," the authority's president, Ted Ferris, said of the building scheme.
Finishing on time and on budget is no small task, particularly given the complexity of certain elements of the job, like building the roof or the massive moving tray that will allow the entire turf field to roll out. An array of machines and concrete forms are needed at different times for different tasks, so scheduling construction to keep the various mechanical monsters out of one another's way was vital. Otherwise, the construction site would take on the look and efficiency of a game of Twister.
A CHALLENGING JOB
One of the project's masterminds, Hunt construction manager Charlie Prewitt, said the project presented several vexing issues. First, he wanted to give workers plenty of time to finish interior work, from locker rooms and seats to luxury boxes and concession stands, with a roof overhead.
But the toughest problem was figuring out when, where and how to build the stadium's two enormous Brunel roof trusses, named for the engineer who devised their particular style for an English railroad bridge in the mid-19th century. When fully assembled, each of the giant trusses will be as long as three Boeing 747 jets placed end to end, as tall in the middle as six London double-decker buses and weigh as much as 400 fully-loaded Hummers.
The trusses will bear most of the weight of the stadium's roof, whose retractable panels will slide open atop the trusses. The trusses and panels together will weigh as much as a small ship. Smaller roof-support structures eventually will connect to the Brunel trusses.
Prewitt wanted a way to start building them sooner, allowing the roof to go up earlier.
Another challenge was how to most efficiently use the concrete forms that shape the stadium's structure, and how to use the giant crane that hoists those forms into place. That crane and several smaller ones are positioned inside and outside the bowl to build the structure. Eventually, they must be moved to make way for other equipment.
THINKING VERTICALLY
Each section has uniquely shaped concrete forms used to build the structure. First, support columns are poured. Then a 2-foot-thick slab full of wafflelike indentations is poured atop the columns to make the next floor. Then another set of columns. Then another slab. So it goes until workers reach the top level of the structure. Starting times for each section are staggered.
Building sections in this manner allows concrete forms to be immediately reused by slipping them out from under one slab floor with a crane and raising them up to pour the same section's next level. In a circular construction routine, work would jump from one section to the next at the same level, requiring constant changes in concrete forms.
This efficiency also allows the giant crane to stay in one area at a time, rather than circling the stadium.
When the northern and eastern sections of the stadium are finished, a milestone expected in August, the same forms will be used in a similar order on the southern and western sides.
Had the circular method been used, assembly of the roof trusses could not have begun until the entire stadium frame was finished. At that point, workers would have begun to build the trusses high above the stadium floor, with shoring beneath to support them.
Truss assembly will start on the stadium floor when the northern half of the structure is done. The trusses will be raised into place upon completion.
"This makes it safer. They are not working 200 feet in the air . . . which makes it a lot easier to do," construction manager Charlie Prewitt said.
RAISING THE ROOF
Assembly of the northern halves of the trusses will start on the ground inside the stadium as soon as the northern concrete work is finished. All of the equipment used to build the concrete frame at the northern end will shift to the southern end, making room for equipment needed to build the trusses at the northern end.
"The good thing you get out of this is you can start building trusses about three months earlier," construction manager Charlie Prewitt said. "That means you get the roof on three months earlier, which gives you about three months extra to do interior work."
When constructing the trusses, the mazes of steel beams will be assembled on the ground. Their northern ends will be placed in special concrete channels, allowing them to be lifted onto the stadium's supercolumns, four oversize concrete pillars that will support the full weight of the retractable roof.
As the southern concrete structure is being finished, making the bowl complete, work starts on the southern halves of the trusses. The roof panels will be attached, and the entire contraption will be slowly jacked into position atop the supercolumns in February.
Once the trusses and roof panels are atop the supercolumns, builders can put the "lid" on the stadium. From there, it's simply a matter of adding the final ingredients: a finished interior and the movable field.
Runner-up is protesting stadium-operation pick
