ABC11 Eyewitness News Reports:
A portion of I-40 damaged by Hurricane Helene will not be fully repaired until 2028, according to the North Carolina Department of Transportation (NCDOT).
The five-mile stretch of damage begins at the Tennessee state line, with an estimated repair cost of $1.36 billion. Currently, one lane in each direction is open to travel, with speeds reduced to 35 mph.
NCDOT has set up a temporary causeway to allow workers and equipment to access the damaged roadway. By harvesting stone from the site, costs have been reduced by about two-thirds, and construction time has been cut nearly in half.
Right now, all traffic on I-40 in western North Carolina is traveling on two lanes after the other two lanes were washed out by flooding.
What is the permanent solution?
Engineers told ABC affiliate WLOS that they plan to build massive retaining walls of roller-compacted concrete, a material more often used in dam construction. These walls will be up to 30 feet thick and anchored directly into bedrock. Another technique being used is an interlocking pipe pile wall, which involves drilling continuous steel casings into bedrock to form a sealed wall face.
“These are technologies rarely used in North Carolina road construction,” Josh Deaton, division construction engineer, said. “This site demands it. Our structures are being designed to withstand the same forces that Helene brought last year.”
WLOS also reported that sensors are buried along slopes to provide real-time alerts of any movement.