How do you cut the time to construct a stadium in half?
For some general contractors, they fast-track a project, issuing bid packages before a project’s designs are completed.
For others, design-build is used as a means of cutting costs and expediting a project.
But for Vance Brown Inc., of Palo Alto, CA, and the $115-million Stanford Stadium under construction at Stanford University in Stanford, CA, “The project delivery method is a hybrid between fast-track and pure design-build,” explained Vance Brown’s Senior Project Manager Rodney Humble.
“The difference is that with our hybrid project delivery method, the project is designed to the contractor’s parameters in order to achieve our deadlines,” Humble continued.
“Typically,” he said, “with the hybrid method, structural engineers meet to discuss constructability issues upfront. Then, they design to those parameters.
“Meetings,” he added, “are held daily with all contractors to discuss issues, schedules, manpower and materials. We have evolved this system since the late 1960s. It is a productive and cost efficient method of project delivery because there is less overhead and therefore a lower project delivery cost for the developer or client.”
Humble’s company is using its hybrid method of project delivery for the demolition of the 85,500-seat Stanford Stadium built in 1921 and is using it for the new 50,476-seat stadium.
Humble said his project team was challenged from the very beginning of the project because demolition of the old stadium had to be completed in two weeks.
The original stadium, according to Ray Purpur, senior associate athletic director of facility, operations and finance of Stanford University, was an earth berm stadium that had been constructed “like an ancient amphitheater in Pompeii.”
The playing surface, he explained, was dug out and below grade. It was then built up and the stadium was constructed around it.
Demolition consisted of removing wood plank seating, an arcade wall around the top of the stadium that was made of gunite and wood, and all the rooms underneath the arcade wall, he added.
The footprint of the old stadium was 601,000 sq. ft.
“The demolition actually took 12 working days. One interesting part about the demolition,” Purpur said, “was that the footings for the south scoreboard were deeper than we thought. These concrete footings had to be jack-hammered out.”
The demolition also included a three-story, wood and steel press box building constructed in 1960.
“This demolition was more difficult than expected. It required multiple attempts at demolition. Using heavy construction equipment, they keep chewing it up like a Pac Man,” Purpur noted.
Humble said that in order to demolish the old stadium in two weeks, two eight-hour shifts were used. Each shift used eight excavators per shift. These consisted of Caterpillar 325s and Caterpillar 345s with thumb attachments.
In addition to the tight schedule for the demolition, Humble said, “several bad rain storms,” posed a challenge to the project team.
“The equipment slid,” he noted, adding that the solution was to cut intermediate benches into level platforms. These platforms were 25 by 1,500 ft. (7.6 by 457.2 m) .
A Caterpillar 963 loader and a Caterpillar D6 bulldozer were used on these platforms to continue demolition during the severe rain storms.
“We also regarded the field and rocked it. We took the existing field and re-sloped it two percent for drainage. To accomplish this, a Caterpillar blade and a Caterpillar 350 excavator was used,” Humble added.
The demolition subcontractor was Ferma Inc. of Mountain View, CA.
Ferma used 12 people per shift during the demolition work. It also used 8-112 dump trucks per shift to haul the debris away. The excavation subcontractor was Don Tucker and Son of Gilroy, CA. The excavation subcontractor used six people per shift.
“Once the old stadium was leveled to the ground, the debris was separated. Two Caterpillar 345s with shears were used to cut up the 100-foot (30.5 m) long steel girders and then haul them away from the site. All of the aluminum benches and galvanized steel was recycled, while the concrete was turned into base rock that was used for access paths around the site,” Humble explained.
Purpur said demolition began Nov. 27, 2005 and it was completed in two weeks. Construction of the new stadium began Dec. 12, 2005 on the project’s 18.4-acre site.
He said the new 50,476-seat concrete stadium will have 30,000 fewer seats so that the new stadium can be built in the 601,000-sq.-ft. footprint of the old stadium.
The seating capacity reduction allows Stanford University to offer new amenities. These amenities will include larger seats (20 in. wide compared with 17 in. wide) and increased leg room (30 in. versus 24 in).
In addition, the upper deck will feature aluminum bleachers, and the lower bowl will be buff-colored concrete.
There also will be new concession stands, a new press box with cabling and communications equipment, a new sound system, closed circuit television (CCTV) at the concession stands, a CCTV security system, and compliance with the Americans with Disabilities Act (ADA), Purpur pointed out.
A new scoreboard at the south end of the football field will match a three-year old scoreboard from the old stadium, he said.
The new stadium also will feature a 40,000-sq.-ft. esplanade with artificial grass at the top row of the north end zone area and a 25,000-sq.-ft. esplanade with artificial grass at the top of the south end zone area.
Essentially, the esplanades will be located on top of the backfill of the old earth berms.
One of the challenges facing the project team in constructing the new stadium, according to Humble, is its 554 caissons.
The caissons range in diameter from 30 to 36 in. (76.2 to 91.4 cm). The depth they need to be placed ranges from 40 to 80 ft. (12.2 to 24.4 m). The caissons are being installed by Malcolm Drilling Inc. of Hayward, CA, the project’s drilling subcontractor.
To install the caissons, Malcolm Drilling is using a Caterpillar excavator with a drill attachment. By early January 2006, 250 of 554 caissons were already installed, he said.
“Typically,” Humble said, “caissons go into a grade beam. Here, they are going into 24-inch round columns that were topped with steel base plates to allow for support of the steel riser system. The steel riser system will support the stadium’s upper bowl. The seating will then be tied into the upper bowl.”
He continued, “Our tolerances are extremely critical. For this reason, we have a staff of six engineers on site to monitor the layout and horizontal and vertical controls to assure accuracy of the tolerances at the 6,000 psi concrete caissons.”
The new stadium also will feature a 38 ft. (11.6 m) tall mechanically-stabilized embankment wall system that will consist of 30-sq.-ft. (2.8 sq m) concrete reinforced steel panels to construct the back wall of the entire concourse level, Humble noted.
The lower bowl, Humble pointed out, will be constructed of 4,000 psi San Diego buff-colored concrete.
The old stadium featured four 120-sq.-ft. (11.1 sq m) grade level tunnels that provided access and egress to the stadium.
These tunnels not only will remain and be used for the new stadium, but three new poured in place horizontal concrete tunnels will be constructed.
The three new 100-ft. (30.5 m) long concrete and rebar tunnels will be stated in February, Humble added, noting that the tunnel subcontractor, Magorian Mine Services Inc. of Auburn, CA, will take four months to complete them.
Other new construction will include a 75,000-sq.-ft. press box. The press box will tie in to an existing elevator shaft.
It will be constructed using structural steel concrete, precast concrete, a storefront glass and aluminum system, and Tepco electric windows that will face the field.
Construction, Humble said, is being assisted with two to three 42- to 57-yd. (38 to 52 m) capacity Putzmiester concrete pumps.
The new stadium also will feature 20 ticket selling windows. The ticket selling windows will be located on the north end, south end and west end of the stadium. Depending on their location, the ticket selling windows will be made of either a wood-framed with plaster or concrete, Purpur said.
Parking for those attending Stanford Cardinal football games will be provided by an existing 11,000-car parking lot, Purpur added.
He said new passenger drop off areas are still being designed. In addition, he said, Caltrans has an above ground high-speed rail that will stop near the stadium on game days to provide public transportation to and from the new facility when home games are scheduled.
Purpur also said that construction of the new stadium is being facilitated by an area developer, John Arrillaga, who also is a major donor, Humble added.
Humble added that Vance Brown has done work for Arrillaga and has used its hybrid fast-track/design-build method of project delivery to facilitate and cut costs for projects the general contractor has done for him.
Vance Brown’s project delivery method will result in cutting the project’s construction time in half, from 18 months to nine months, Purpur said, adding that construction is scheduled to be completed by Sept. 15, 2006. CEG