Greenfield Bridge to be imploded; replacement work to last a year
More than 20 years of catching concrete crumbles above one of Pittsburgh's busiest highways has persuaded city officials to demolish the once-magnificent Greenfield Bridge.
The city intends to implode the 89-year-old bridge onto the Parkway East more than 100 feet below in 2014 and rebuild it, said Patrick E. Hassett, assistant director of Pittsburgh's Bureau of Transportation and Engineering.
"It's going to be nuts," Councilman Doug Shields said on Wednesday after Hassett briefed city council on the project. "You close that bridge down, where is that traffic going to go• There aren't a lot of good alternatives."
Major traffic headaches appear unavoidable.
The 15,000 drivers who use the bridge daily will need to find another way from Greenfield to Schenley Park for at least a year during rebuilding. The demolition will close the six-lane parkway for "four or five days" during Christmas week, when traffic is expected to be lightest, Hassett said. The 300-foot-long bridge will reopen in early 2016.
Carmine Conicella, 57, an owner of nearby Conicella's Pizza on Greenfield Avenue, said the bridge closure would not hurt his business, a 30-year neighborhood mainstay catering mainly to residents, but it would wreak havoc with traffic.
"It's bumper-to-bumper now," Conicella said. "Imagine when they close it. I don't know how they're going to get around."
Officials estimate the project's cost at $17 million. Pittsburgh will cover 5 percent of the cost; the state and federal governments will pick up 15 percent and 80 percent, respectively.
The span is one of 16 structurally deficient bridges the city owns, Hassett said. PennDOT classifies nearly 7,400 bridges across the state as structurally deficient, meaning one or more of the main components has deteriorated. About 1,900 are in the 10-county area surrounding Pittsburgh.
The city built what it then called the Beechwood Boulevard Bridge in 1922 as a main entrance to Schenley Park. At the time, Lewis' Pittsburgh Street and Trolly Guide proclaimed it the largest single-span concrete bridge in the United States.
"The design is such that despite its extreme weight and strength, the impression that it gives is of grace and lightness," the guide stated.
It evolved into a Pittsburgh gateway after the parkway opened, but in recent decades netting covered its arches.
In 2003, a football-sized chunk of concrete critically injured Kerry Ann Long of Turtle Creek when it crashed through her windshield as she drove beneath the bridge. She claimed in a lawsuit against the city and PennDOT that the chunk came from the bridge. The city argued in court filings that it did not fall from the bridge, because inspectors found no holes in the netting large enough to let the chunk through.
Long and the city settled the lawsuit out of court in 2005.
Hassett, who lives in Greenfield but rarely has occasion to cross the bridge, said the city considered rehabilitating it, but a new bridge promises a longer life span. A rehabilitated bridge would last 30 to 50 years, compared with 100 years for a replacement.
To implode the bridge, workers would set explosive charges along main structural supports so the span collapses onto the parkway, which averages about 56,000 drivers a day. Contractors would cover the highway below with a deep bed of dirt to protect it.
"It's going to be a first for this area, in terms of dropping a bridge like that onto an interstate," Hassett said. "It's been done before, but not around here."
Contractors would first remove netting and a mini-bridge built under the larger one to protect vehicles from falling concrete. That would happen over a weekend and require a parkway closure.