Explaining Accelerated Bridge Construction; method used on local - WRCBtv.com | Chattanooga News, Weather & Sports

Explaining Accelerated Bridge Construction; method used on local bridges

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File photo of Dade County bridge construction. File photo of Dade County bridge construction.
DADE COUNTY, GA (WRCB) -

The method used to construct the Florida bridge that collapsed on Thursday is not uncommon. In fact, GDOT used an accelerated method to replace one in Dade County.

It’s been about a year since the State Route 299 bridge over I-24 was replaced with a new structure. The structure was built using what's known as accelerated bridge construction, or ABC.

"It’s a technique of being in a hurry,” said Steve Wright, with Wright Brothers Construction.

It's a common strategy meant to finish projects faster, minimize traffic, and be more cost effective.

READ MORE | UPDATE: Dade Co. bridge built in same manner as Florida pedestrian bridge

"The ability to repair bridges quickly has come to the forefront because an awful lot of the interstate era projects those bridges and that kind of stuff are reaching the end of its life,” Wright explained.

Wright knows firsthand how the process works, his company used it to construct the SR 299 bridge in Georgia.

"All we did was build it in place and pick it up and move it, that was the accelerated part of it,” he explained.

Sky3 flew over the construction last May when the company moved two new sections into place without shutting down the interstate. Wright says this bridge is fairly simple compared to the pedestrian bridge in Florida which was more complex.

"There’s some risks that if you don't get them right then there will be some much bigger forces in the bridge than you might have expected,” said John Stanton, Professor of structural engineering, University of Washington.

The bridge in Georgia took several months to build, then about 60 hours to move into position. The one in Florida took just six hours.

Wright said he wouldn't blame the acceleration process for the collapse.

“There are a lot of bridges that aren't accelerated at all that’s sometimes there's troubles in the actual construction of it. My opinion would be that the accelerated part of that nothing to do with the failure,” he said.

Wright tells us he plans to review the investigation once it's complete and discuss the findings with his staff.

The company that built the Florida bridge said it's cooperating with investigators, but this is not the first time the company's been under scrutiny. It was sued when a makeshift bridge collapsed and injured a TSA worker at Ft. Lauderdale’s airport. That case is still pending.

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