MADISONVILLE, Ky. (Sept. 19, 2023) – The Kentucky Transportation Cabinet plans to conduct testing of the US-41 Southbound Twin Bridge over the Ohio River starting Sept. 25 and continuing through Nov. 18.
This testing initiative will assess the structural integrity and safety of the bridge.
The federally-mandated inspection will require single-lane closures on the bridge from Monday, Sept. 25, through Nov. 18. Digital message signs have been placed on US-41 South notifying motorists of the work in advance of the closures. During this period, one of the two lanes on the US-41 Southbound Bridge will be temporarily closed.
All structures carrying public roads in the United States undergo a routine inspection every 24 months. For certain spans, like the Twin Bridges, a hands-on inspection of critical members is also performed. This biennial inspection was completed on the US 41 SB Bridge in Aug. 2022. While that inspection report contained no critical findings for the bridge built in 1965, the upcoming inspection is more specialized. It will involve removing paint, testing hundreds of welds and replacing primer.
To accommodate the equipment required for testing on the bridge, KYTC will restrict all truck traffic to a maximum width of 12 feet, prohibiting wide loads during the testing period.
The Southbound US-41 Bridge is the only span in the Department of Highways District 2 region that will undergo this type of inspection. It contains “T-1” steel – a grade of high-strength, quenched and treated steel known for being highly amenable to welding and machining. However, in May 2021, a fracture was discovered in a weld – referred to as a “butt weld” – in a T-1 steel component of the Interstate 40 Hernando de Soto Bridge between Memphis, Tennessee, and West Memphis, Arkansas.
As a result, the Federal Highway Administration (FHWA) in December 2021 issued a memorandum to states to identify, inspect and test specific T-1 steel bridges to verify the soundness of all butt welds with the use of non-destructive testing. FHWA asked that all the projects be completed by March 31, 2024.
Michael Baker International, an engineering firm instrumental in the emergency repair of the Interstate 71/Interstate 75 Brent Spence Bridge between Covington and Cincinnati following a fire in 2020, will lead the inspection and testing.
Motorists should anticipate delays and potential traffic backups due to lane closures and restrictions.
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