Did Someone Order an Instant Bridge?
April 17, 2012
By JOHN SCHWARTZ
Read More: http://www.nytimes.com/2012/04/18/us...general&src=me
Timelapse Video: http://nyti.ms/IVumhu
By using “accelerated bridge construction” techniques, a collection of technologies and methods that can shave months if not years off the process of building and replacing critical infrastructure, Massachusetts is at the forefront of a national effort that is aimed at putting drivers first.
- “This will be the new normal,” said Victor M. Mendez, the head of the Federal Highway Administration. Quick replacement of bridges, however, is anything but intuitive, he said. “If you haven’t seen it, it seems kind of odd that you’ll pick up a bridge and slide it into place,” he said. As the sun climbed into the sky on Sunday, the new River Street Bridge, 400 tons of steel and concrete, rode on a set of trailers and high supports that adjust to keep the span as level as a tray of drinks balanced on a waiter’s hand. Jaiden Rivera, 7, watched the operation from the other side of a chain-link fence with his grandfather, Eddie Anderson. Mr. Anderson invited his five grandchildren to sleep over so they could be there to watch a bridge moved and slipped onto its abutments like the world’s biggest Lego block.
- Get a bridge replaced in days, not years, and “there’s ‘wow,’ ” said Theodore Zoli, national bridge chief engineer for HNTB Corporation, who has received a MacArthur “genius” grant for his innovative work on bridge construction. Nowhere have the various techniques for speeding bridge work been more enthusiastically embraced than in Massachusetts, which replaced 14 bridges on Interstate 93 last year over 10 weekends. But similar techniques are being used around the country, from Mesquite, Nev., to the Golden Gate Bridge in San Francisco, which is getting 300 feet of new roadway one 25-foot prefabricated section at a time, 78 pieces in all. “We have a bridge that we simply cannot close to traffic,” said Ewa Bauer, chief engineer for the Golden Gate Bridge Highway and Transportation District.
- Prefabrication techniques allow Ms. Bauer’s crews to close individual lanes instead of shutting down the bridge. Since February, they have torn out and installed one length of deck each night, and they have already completed a third of the task, she said. None of the techniques is quite as eye-popping as “heavy lift” — when a hunk of bridge is simply picked up and put into place. Time and the elements had not been kind to the steel and concrete of the old River Street Bridge, which stretches over railroad tracks used by freight and commuter trains. The bridge also needed raising — an additional 18 inches would allow double-decker commuter trains to pass underneath. So the Massachusetts Department of Transportation got to work.