INDIANAPOLIS— A portion of the newly-opened Interstate 69 extension that was built on top of a mine in Pike County has sunk several inches.
The 250-foot section, made of dark asphalt designed to be more flexible than concrete, is part of the lead-up to the Patoka River Bridge. It will be fixed in the coming months, said Indiana Department of Transportation spokesman Will Wingfield.
“Even though I-69 is now open to traffic, construction is not completed. INDOT’s maintenance and construction personnel that have been monitoring this, and the settlement is not an issue that requires an immediate response,” Wingfield said.
“INDOT will work with its contractors to make repairs as part of the normal process in inspecting and closing out a construction contract. This could be as simple as sealing the pavement and adding additional asphalt where needed.”
Transportation officials for years expected some settling to occur at portions of the highway built atop old mining areas in Gibson and Pike counties.
As the state drew up plans for the 142-mile highway extension, its project team studied soil samples, and construction contractors performed a process called “deep dynamic compaction” that involved dropping a 15-ton weight from 30 feet in the air. Contractors used dark asphalt rather than lighter-colored concrete to pave those sections.
The lead-up to the Patoka River Bridge was mined just before the highway’s construction, which transportation officials said could be the cause of the additional sinking.
Wingfield said there is no timeline for fixing the 250-foot section and that the sinking that has taken place so far is not dangerous for drivers, but that the state typically moves quickly to close construction contracts.