Kentucky Transportation Cabinet officials have finalized plans to demolish the old Ledbetter bridge, which spans the Tennessee River from McCracken to Livingston counties.
The 83-year-old structure, which has been closed to traffic since July 2013, has become unstable because of land slippage along the McCracken County river bank following recent heavy rain. While the main truss spans are stable, two spans near the west approach decking have dropped more than 5 feet, according to the cabinet.
Haydon Bridge Co. and Kay and Kay Construction Co., who jointly built the new U.S. 60 Tennessee River bridge, will demolish the old structure under a change order to its contract totaling $5.62 million. Work is to begin immediately, with the first step being to bring in equipment and conduct an engineering analysis.
The cabinet had already let bids for the demolition, but looked at different options when those bids came in $3 million higher than the $5.4 million estimate.Work is to begin June 10 and scheduled to be completed by Dec. 1.
"It's going to take awhile, most people don't realize," said Keith Todd, Transportation Cabinet spokesman. "It's more of a deconstruction. There will be some implosions, but a lot of other parts will be taken down piece by piece."
According to Todd, one of the goals is to keep the river open to traffic as much as possible. The process will allow time to consult with the U.S. Coast Guard as the project progresses and try to avoid closing the river for long periods at once.
On Thursday, a seismic sensor was attached to the bridge to alert inspectors of major movement in the sagging approach spans.
The old bridge opened to traffic in 1931. It was reduced to a 3-ton load limit in January 2012, which led to expedited opening of the new bridge on July 31, 2013.