A major drop to a section of the old Ledbetter Bridge delayed river traffic and could expedite the demolition of the 83-year-old bridge which spans the Tennessee River from McCracken to Livingston counties.
Keith Todd, Kentucky Transportation Cabinet spokesman, said inspectors were investigating the cause of a five-foot drop of two sections near the west approach decking on the McCracken County side of the bridge that began late Tuesday night. The portion sank nearly two feet overnight, then continued to decline Wednesday for a total fall between five and six feet, McCracken County Emergency Management Director Jerome Mansfield said.
The 1930s-era metal bridge has been closed since last July when the new $66 million Ledbetter Bridge opened.
Todd said initially engineers believed the drop could be related to problems at the top of the pier found during a structural analysis in 2011. Those findings, which showed cracks in the concrete and rusting of the trusses, girders and beams, led to imposing a three-ton load weight limit in January 2012.
On Wednesday, senior bridge engineers from Frankfort were on scene along with officials from the sheriff's department who were in the water checking beneath the bridge.
Todd said engineers believe the cause of the drop was movement on the bluff near the bottom of the pier. An inspection found land along the bluff at the base of the approach piers had moved downhill several feet, causing the two approach spans to drop about three to four feet where they join.
Todd said the bad winter and heavy rains across the region, coupled with the ground frequently freezing and thawing, resulted in land slippage and erosion. According to the National Weather Service, more than three inches of rain fell in the past three days.
The new Ledbetter bridge opened to traffic last summer, 11 months ahead of schedule. The advanced completion of the new bridge was considered necessary after officials imposed the lower load limit to help prolong the life of the aging structure.
Mansfield said he is working with the state Department of Emergency Management to have a geotechnical specialist perform a survey of the bridge's structure. The Federal Highway Administration could also send representatives to analyze the situation.
A "No trespassing" fence and warning signs were placed near the McCracken County side of the bridge, the sheriff's department was on scene for traffic control and individuals were told to avoid that area.
The U.S. Coast Guard in Paducah closed the Tennessee River from the 4.8-mile marker to the 5.8-mile marker for several hours during the afternoon while KYTC engineers evaluated the bridge. Lt. Dan McQuate said the engineers were specifically evaluating whether the collapse of the first span of the bridge - the span that was reportedly sinking - would cause a domino effect on the rest of the bridge.
The evaluation determined the impending collapse would not affect the rest of the bridge, so the Coast Guard allowed boat traffic to continue through the channel spans. They placed one restriction: no stopping within a quarter mile of either side of the bridge. The stipulation was aimed at recreational boaters or sightseers.
The closure of the Tennessee River had little effect on the river industry, but a long-term closure could create a problem for barge companies. Harley Hall, vice president of river operations at James Marine, said his company has eight boats on the river that would be affected.
A closure would mean those boats would instead have to travel the Cumberland River, which is much more narrow and has a swifter current. The detour would more than double the trip's length, which would cost time and money.
"We're going to keep running," Hall said. "(A detour) would cost us money, but hopefully it won't be an issue."
Other barge companies have vessels on the Tennessee, and ships also use the Tennessee River to get to rock quarries on a daily basis.
The transportation cabinet has plans to demolish the old bridge and put demotion out for bids April 20. Three bids were received, and all were above the engineer's estimated cost of $5.4 million. The lowest received bid was $8.4 million.
Todd said typically bids that are 15 percent more than the estimate are automatically rejected. But due to the need to act quickly, the bids are being evaluated and a decision to either accept one or rebid the project will be made within the next few days.
McCracken County Emergency Management will be taking the lead to monitor the bluff slippage. Mansfield said none of the homes along the bluff have been evacuated.
The agency set up a command post and will have personnel monitoring the situation. Mansfield also requested personnel from the U.S. Army Corps of Engineers and the Kentucky Geological Survey to be on site.
"Residents along the bluff should be diligent and report any unusual sounds, land movement or cracks in the soil so prompt action can be taken," Mansfield said. "Anyone who sees anything unusual should report it to the local 911 call center immediately."
Contact Kathleen Fox and Corianne Egan, Paducah Sun staff writers, at 270-575-8650 or follow @kathleendfox and @CoriEgan on Twitter.
terry love posted on: Thursday, May 01, 2014 10:38 AM
Title: ledbetter bridge
well there you go the fill the city needs for the marina