I-40 bridge at Memphis likely closed for several months
May 19, 2021
It may be several months before motorists can get back on the I-40 bridge at Memphis.
On May 18, the Arkansas and Tennessee Departments of Transportation announced a loose timeline of when the Hernando de Soto Bridge across the Mississippi River along Interstate 40 will reopen. As of Wednesday, May 19, transportation officials are estimating it will take several months to finish repairs.
TDOT awarded the contract for emergency repairs to Kiewit Infrastructure on Monday, May 17. Work on repairs is expected to start this week. According to TDOT, repairs on the bridge will be done in two phases:
- Phase I: Addition of two 30-foot steel plates (18,000 pounds each) on either side of the fracture to strengthen the bridge for contractors and equipment to safely work on Phase II repairs. Kiewit will commit to working 24 hours a day until work is completed. TDOT expects the fabrication of the steel plates to be completed by Wednesday.
- Phase II: Cut out and replace the damaged part and inspect the bridge for any additional concerns that need to be addressed before traffic returns to the bridge.
Traffic cannot safely return to the Hernando de Soto Bridge until both phases are completed.
As of publication, there was no estimated reopening date. Assuming favorable weather conditions, TDOT said it would take several months to complete the repairs. TDOT stated better estimates will be available as repairs progress.
In the meantime, motorists traveling on I-40 eastbound in Arkansas are to take Exit 5 to Interstate 55 to cross the Mississippi River into Memphis. Those traveling westbound on the Tennessee side of I-40 should take the Interstate 55 bridge across the Mississippi River to get into Arkansas. From there, take Exit 4 to access I-40 westbound.
With the I-55 bridge being much older than the Hernando de Soto Bridge, many motorists are concerned about the safety of that bridge. Addressing those concerns, TDOT is sending out two inspection teams with drones to work on the I-55 Mississippi River Bridge. According to a news release, TDOT “is using an overabundance of caution in reviewing new footage and previous inspection reports to verify the safety of the older bridge.”
For more information about progress on the Hernando de Soto Bridge, visit a website dedicated to the issue here.
Questions about inspection process
On Monday, ARDOT Director Lorie Tudor confirmed reports of drone footage from 2019 showing the fracture on the Hernando de Soto Bridge. Tudor blamed a single inspector for missing the fracture during both the 2019 and 2020 inspections. That inspector was terminated Monday morning.
“We are in the process of referring this matter to the proper federal authorities for their determination if further investigation, criminal or otherwise, is warranted,” Tudor said. “However, this is not about the failure of one employee. This is about a failure in the inspection process that allowed this to happen.”
Tudor said ARDOT plans to increase redundancies in the inspection process to prevent future incidents, including combining drone footage. Another way to inspect bridges is called nondestructive testing, including ultrasound and eddy current.
With ultrasonic testing, inspectors use an instrument and probe to pulse high-frequency sound waves into the material at precise intervals and angles. When a wave encounters a defect, some of that energy reflects back to the probe like an echo. The signals are analyzed by the test instrument and presented on the instrument’s screen for the technician to interpret, not unlike a medical ultrasound.
Eddy current testing involves a similar concept but uses an electromagnetic field to induce electrons to flow from the probe into the material. Any discontinuities in the metal will distort the flow of electrons, which is captured and analyzed by an eddy current instrument.
Wayne Waxman, director of marketing at Zetec, explained how this new technology can detect the beginning stages of the crack like the one on the Hernando de Soto Bridge before it becomes visible to the naked eye.
Zetec produces instruments, probes, software and other nondestructive testing technology.
“The field of (nondestructive testing) includes sophisticated digital technologies that can highlight tiny flaws on and beneath the surface of metal or a weld, including corrosion, heat damage and other discontinuities,” Waxman said in a statement. “They help you detect flaws that you can’t see with the naked eye and address them before they become a bigger problem.”
Improved bridge inspection processes can save the economy million, if not billions, of dollars in unnecessary delays. According to the Arkansas Trucking Association, the closure of the I-40 bridge at Memphis is costing the trucking industry $2.4 million each day.
“This a critical link for Arkansas,” Arkansas Gov. Asa Hutchinson said during a news conference on Tuesday. “Whenever you see a break in the commerce, whenever you see a defect in a bridge, then you realize how dependent you are on that flow of commerce.”
The bridge closure also highlights the need for a sweeping infrastructure bill. In its quadrennial infrastructure report card, the American Society of Civil Engineers gave bridges a C, down from a C-plus from the previous report. Arkansas received an overall grade of C-minus, with 5% of bridges deemed structurally deficient. Nationwide, 7.5% of bridges are considered structurally deficient. Tennessee also scored an overall C-minus, with 4.4% of bridges structurally deficient. LL