MEMPHIS, Tenn. — Six months after the Hernando DeSoto bridge between Memphis and Arkansas was closed due to a fractured steel beam, Arkansas transportation officials say inspections are complete.
Arkansas Department of Transportation Director Lorie Tudor made the announcement Thursday morning:
“ARDOT is grateful that the bridge investigations are complete. We will now move forward with confidence and make the changes necessary to improve our program so that the past will not be repeated. Our highest calling as public servants is the safety of Arkansas’ road users. We appreciate Arkansans support and encouragement as we have navigated this difficult journey, which began exactly six months ago on May 11,” Tudor said.
A nearly 100-page ARDOT Bridge Inspection Program Assessment Final Report details findings from the Federal Highway Administration. The assessment was done at ARDOT’s request.
The report states the fracture happened in a “welded splice” between two plates in the bridge’s tie girder. The first fracture reportedly happened in a spot where two weld repairs had been performed.
ARDOT’s report states the cracking in the weld likely occurred within hours of its completion but went undetected for years. The beam was fabricated in the 1970s.
The report states the fracture happened in three phases. The first reportedly happened on “the interior face of the box,” where ARDOT says it would not have been visible by conventional inspection.
ARDOT says the second phase of the fracture happened “through the remaining thickness.” That crack was later scene in drone video taken in 2019.
The third phase of the fracture reportedly happened across the top flange of the bridge. The report says the existing weld cracks likely became unstable as a result of “unique combination of low temperatures, increasing tie girder stress, and the effects of live loads to which the bridge had not been previously subjected.”
The report says it is “highly unlikely” that a similar fracture will happen again, but it is still crucial to continue “arms-length” inspections that focus on spotting any new visible cracks at that spot.
The report outlines several recommendations for the state’s bridge inspection program, including a registered professional engineer be on site for the inspection of complex and major bridges due to the significant risks of impacts to the public from closures. See the full report here.
The bridge, which carries nearly 40,000 vehicles a day on Interstate 40, was abruptly closed May 11 after an inspector found a fracture that had been missed by previous inspections. It began reopening July 31 after repairs were made.
This comes after seeing the ARDOT Bridge Inspection Manual does not indicate the need for any specialized inspector qualifications, experience, training or certification beyond the minimum required of a team leader by the National Bridge Inspector Standards.
Beyond reviewing written policies, interviews with staff were conducted as well. After some of the interviews, the report said, “…it was conveyed to the Team that there have been many policy or procedure changes implemented through email and it was difficult for inspectors to keep track of the changes and then subsequently certify that they understood the changes.”
During the months of closure, traffic was routed to the older Interstate 55 bridge, causing hours-long traffic backups for truckers and commuters passing through one of the major shipping routes across the United States.
According to the report, investigators were able to verify that a crack in the side of the bridge had been visible since at least 2016.
The inspector who was directly responsible for inspecting that part of the bridge in 2016, 2017, 2019 and 2020 was fired.