Initial work has started to fix a gaping sinkhole in the middle of South Main Street “described as “big enough to park a Volkswagen in.”
City of McAlester Public Works Director Jeb Jones said Friday he’s hopeful surface repairs on the section of South Main with the sinkhole can be completed soon enough to reopen the street to traffic by next week, depending on the weather.
“We hope to have the road open by the middle of next week,” Jones sad.
However, repairs involving pumping concrete underground to fill portions of a damaged storm drain blamed for the street collapse are expected to continue for an estimated additional five work days even after the street is reopened to through traffic.
“The road is wide enough to create a work zone in the middle of the street,” Jones said.
What about the motorists who sometimes zip through the street at a high rate of speed while trying to catch a green light?
Jones said they will have to remain mindful of the work zone.
“They will have to slow down,” he said.
The sinkhole resulted from a large section of the street collapsing around a manhole, into an underground storm water drain, just south of the traffic signal where South Main Street intersects with Wyandotte Avenue. That prompted the city to set up barricades and close that part of South Main Street to all traffic, with most of the traffic detoured to South Second Street.
City councilors voted unanimously this week to fund a $56,318 contract with Crowder-based Advance Construction to complete the task. Councilors acted under a “new business” designation on the meeting agenda. City Manager Pete Stasiak said details of the means to repair the sinkhole came together after the deadline for placing items on the regular meeting agenda had expired.
Stasiak said he sent a total of three requests for bids on the project, but only received the one response.
McAlester City Attorney John T. Hammons determined the method used to get the quotes would not be valid to follow bidding procedures under normal circumstances, but he said it was in-line for an emergency.
Stasiak said he ran the $56,318 price for the construction project by the city’s engineers, who said it sounded reasonable for the job.
McAlester Vice Mayor/Ward 2 Councilor Cully Stevens asked why the Oklahoma Department of Transportation was not paying for the project. South Main Street in McAlester is part of the U.S. Business 69 Highway, and normally ODOT is in charge of maintenance on the highways in McAlester through an agreement with the federal government.
Stasiak said ODOT will pay for the concrete used for the surface repairs to the street, but the city is responsible for the storm drains and other things below the surface.
“We have about 100 feet of a concrete drain,” Stasiak said, saying it was built in the 1920s and is around 100 years-old.
Jones said Friday a construction worker had already started cutting off the jagged edges in the concrete where the sinkhole had collapsed, squaring them off to make the repair process more uniform.
“You want to true the edges up to remove that jagged material,” Jones said.
The section of street collapsed due to decades of wear and erosion around an underground storm drain beneath the surface in the middle of the street, he said That will have to be repaired but the current plan will allow for the surface repairs to the street to be completed so it can be reopened prior to completing all of the needed underground repairs.
Jones said the technique will use a material called flowable fill, a weaker, concrete-like material often used as backfill or road base material.
“We can pour the road surface and get it back quicker than if we put cut rock in it,” he said.
The sinkhole occurred when captured storm water from the street above continuously flowed into the underground storm drain.
“Over the decades, we feel it scoured a hole in the bottom of the drain,” Jones said. The large underground storm drain is four feet tall and three feet wide, with the top of the drain an estimated three-to-four feet below the road’s surface and the distance from the surface to the bottom of the storm drain about eight feet, he said,
“The street just collapsed into that hole,” said Jones.
He said the storm drain can be repaired after the street is reopened to traffic because the street is so wide. Plans call for a construction crew to go about 60 feet north of where the sinkhole is located and then make a new entrance to the storm drain, using the construction zone island planned for the project after the street is reopened to traffic.
“We will have to go into the storm drain,” Jones said. We’ will have a concrete truck pumping concrete through a hose for from 59-to-60 feet.”
The underground storm drain that’s set for repairs is not part of the manhole that’s been visible in the middle of the street since the surface collapsed.
“That’s for sanitary sewer,” Jones said. “Everything’s all right with it.”
Asked about how cost of the project will be divided with ODOT, Jones said “ODOT is responsible for the road surface. When it comes to underground utilities, that’s the responsibility of the city.”
“We will make the repairs and ODOT will pay for the surface repairs,” Jones said. The city’s contractor will do the repairs involving the underground, utilities at the site, which will be paid by the city,” he said.
Contact James Beaty at email@example.com.