WINNIPEG – The southbound lanes of St. Mary’s Road will remain closed into next week due to a giant sinkhole that collapsed a portion of the pavement on Wednesday.
The city’s public works director told Global News Thursday that work crews had begun back filling the big hole, and hoped to have asphalt work all finished by the beginning of next week when the road will completely open.
Meantime two southbound lanes were open for the Thursday afternoon rush hour; two northbound lanes are expected to be open for the Friday morning rush hour.
“Sinkholes like this are rare,” said Brad Sacher, saying drivers shouldn’t be concerned about other giant voids opening up in roads around Winnipeg.
Sacher said this sinkhole was caused by the sewer pipe disconnecting underground slightly.
“Over time the soil around the pipe finds its way into the pipe and gets washed away into the sewer and a void is created there and it happens very gradually,” said Sacher. “Most of the time that is something very difficult to detect.”
Sacher said city crews do check for the warning signs of sinkholes and typically they are spotted before a serious issue occurs.
While the sinkhole on St.Mary’s Road likely wasn’t caused by the frigid winter Winnipeg just endured, one expert says the cold can cause an increase in sinkholes.
“Particularly this past winter when frost penetrated a lot deeper that it used to into the ground and frozen a lot of the pipes, you should expect some of those pipes may have breaks and water will be seeping out,” said Ahmed Shalaby, head of the department of civil engineering at the University of Manitoba. “That water is eroding some of that infrastructure so it’s not surprising for a sink hole to occur at this time.”
Sacher agrees Mother Nature can create issues with the infrastructure below the pavement.
“It would be really difficult to say with a high degree of certainty that what we will see through the summer in terms of voids under the pavement is a result of the winter,” said Sacher. “We typically have frost in the ground and I wouldn’t anticipate any more frequency than we would normally get but it is always possible that we will see a few cases that were impacted by the deep frost. “
Shalaby said the frequency of sinkholes usually slows down in summer.
“With the warm weather coming in and frost receding into the ground hopefully there will be no more occurrences of this type,” he said.
When it comes to preventing sinkholes, Shalaby said it is impossible to predict one by looking at the road. He said regular inspections of pipes as well as use of radar to detect any voids under pavement will help so crews can repair the issues before the ground caves in.
Sacher said city crews do check for the warning signs of sinkholes and typically they are spotted before a serious issue occurs
The sinkhole appeared at about 3 p.m. Wednesday in the southbound lanes of St. Mary’s Rd. at Morier Ave. Rush hour traffic was diverted east onto mostly residential roads in Old St. Vital, causing delays stretching back into downtown.
Fortunately the void was noticed before any vehicles drove into it. No one was hurt.
On Thursday, the southbound lanes remained closed: one northbound lane was converted to take southbound traffic, which reduced northbound morning rush hour traffic to just two lanes for a few blocks.