Crews have opened up the concrete and enlarged the hole to assess the damage, which was caused by a water main break. (Daniel Mears / The Detroit News)
Detroit — Officials are set to begin filling in a 14-foot deep sinkhole that opened up on Jefferson near Randolph over the weekend, but they aren’t sure how long it will take to make full repairs.
“It could take a couple of days or up to a couple of weeks,” said Michigan Department of Transportation spokeswoman Diane Cross.
“We’re proceeding with caution because there are all kinds of potential problems down there.”
Representatives of gas, water and electric suppliers met Tuesday with officials from AT&T, MDOT and contractors to assess the best way to deal with the problem.
“It looks like the substructure underneath the pavement isn’t safe and reliable yet to put in shoring,” Cross said.
“It’s also necessary to first clean out debris without hitting any of the utility lines. The sinkhole took out all the protective covering for the utilities causing them to just collapse.”
According to Cross, the first step will be to put in enough sand to support the utility lines – especially the gas mains – so they don’t give way.
“Once the sand stabilizes the utility lines, we’ll begin to put up shoring for the walls,” Cross said. “We’ll start pouring the sand Tuesday night or on Wednesday.”
The sinkhole, discovered over the weekend when a taxi cab drove into it early Sunday morning, was originally about the size of a large manhole.
But crews have opened up the concrete and enlarged the hole to at least 10 by 10 feet to assess the damage, which was caused by a water main break. The opened surface exposes the brick structure of a 1890s-era manhole. Crews at the scene Monday said such antiquated structures can be found underground throughout the city.
Several utility services, including DTE Energy, AT&T and the Detroit Department of Water and Sewerage, run through the area, making the area hazardous to repair.
Two lanes of traffic at the intersection, which sits northeast of the Coleman A. Young Municipal Center, have been blocked. Cross suggests avoiding Interstate 375 to get downtown. Instead, he said, take the Lodge.
Cross implored motorists to slow down and drive with caution in the work zone.
“They have to remember that this is an active construction zone,” Cross said.
“Repair crews are working in brutally cold conditions and vehicles zooming up and down Jefferson and Randolph will only make things more dangerous.”