|Launched. State is about to open first precast segmental bridge.|
After an initial failed design-build attempt at replacing an old swing bridge, the New Jersey Dept. of Transportation now plans to open its first precast segmental concrete bridge to traffic later this summer. The 440-ft-long twin main spans of the new Victory Bridge over the Raritan River are the longest match-cast girders of their kind in the U.S., say officials.
In 1999, NJDOT hired a team led by Schiavone Construction Co., Secaucus, N.J., to build the bridge under a modified design-build contract for $90 million. The process called for "completing only 30% of preliminary plans for bidding purposes," says Nat Kasbekar, NJDOT project manager. "The team was picked on a low-bid basis to complete design [and] construction. One drawback of this process is that it does not allow review of the contract."
That resulted in irreconcilable differences over the pier design related to vessel impacts. Schiavone Chief Engineer Paul Scagnelli says its design called for protecting the piers from stronger ship impacts than what NJDOT wanted. "We felt we could not walk away from this knowledge just because they didnt want to believe it," he says. Under design-build, "the state was immune from [risk], but we were not," he says. NJDOT terminated the contract in 2001.
NJDOT started over with traditional design-bid-build. It hired a joint venture of Figg Engineering Group, Tallahassee, Fla., and Vollmer Associates, New York City, in late 2001 to redesign the bridge, a job the team finished in seven months. George Harms Construction Co., Howell, N.J., then submitted the low bid of $109 million, says Kasbekar.
"From the word go we hit the ground running to beat the time constraints," says Ed Panuska, Harms project manager. Foundation work included 68-ft x 28-ft x 18-ft river footings, supported by drilled steel shafts of 8 ft and 6 ft dia, with sockets as deep as 24 ft into extremely tough rock, Panuska says.
|Victory Team. Figgs Reggie Walden (left), Jose Rodriguez and Garrett Hoffman worked with Harms Ed Panuska (second from left).|
Harms used a 330-ft-long underslung gantry to erect approach spans between the pier columns, spaced 150 ft apart. A series of pier brackets supported the gantry as it progressed. The 22 precast post-tensioned piers consist of 360 segments, 90 tons each. Seventy barges carrying precast segments from Bayshore Concrete Products Corp., Cape Charles, Va., arrived continuously at the site. In winter, the segments often froze to the barges, recalls Panuska.
The twin main spans consist of up to 100-ton segments built by balanced cantilever, says Jose Rodriguez, Figg project design manager. Crews eventually erected up to two approach spans a week and four main span segments a day, enabling a 15-month completion of the southbound span by June 8, 2004. That garnered a $500,000 bonus. Late penalties would have reached $9,300/day. Harms completed the north span in April, some eight months early.
The new bridge replaces an old swing bridge that opened up 1,100 times a year, hindering the 25,000 vehicles that used it daily. The new bridge has 110-ft vertical clearance, with two lanes in each direction and 10-ft shoulders, says Reggie Walden, Figg resident engineer. NJDOT now is planning two more precast segmental bridge projects. But as for modified design-build, "currently we do not have any project scheduled for it," says Kasbekar.
(Photo Courtesy of Figg Engineering Group)