May 11, 2009

Another sinkhole appears in Calgary

RICHARD GILBERT

staff writer

For the second time in a week, a sinkhole has formed near a Calgary condominium worksite.

The Calgary Fire Department was recently called to a building in downtown Calgary to investigate reports of a sinkhole in the underground parkade of a condo near a construction site.

The problem was discovered when the front wheel of a pickup truck dropped into the sinkhole.

“When crews from Station #2 and heavy rescue specialists arrived, they observed a sizable hole in the floor of the parkade upon which a pick-up truck was parked,” said a City of Calgary press release.

The incident commander evacuated the building because the hole was adjacent to one of the building’s structural support members.

The heavy rescue team and firefighters removed the pick-up truck and examined the sinkhole.

It is four metres wide by three metres deep and there was a visible connection to the large construction site on the east side of the parkade.

Under the direction of engineers from Lake Placid Developments, the company building the Centuria on the Park condominium project nearby, the sinkhole was filled in using gravel material.

The city also directed the engineers to assess and report on the stability of the adjacent building.

Thirteen residents in eight suites were evacuated from the nearby building and were not allowed to return until the city got an engineering report determining the safety of the complex.

Engineers are also investigating whether the Centuria development project caused the sinkhole’s appearance.

“I am not prepared to make a comment until such time as we are fully appraised by our engineer,” said Steve Seal, executive VP of development with Lake Placid Developments.

“We have retained an engineer and we need to have this team move forward. We don’t have a specific time-line because we want to make sure the proper due diligence is carried out.”

A Calgary city alderman said crews are also looking closely at the safety of other excavation sites.

“There is work being done now to find out how long these other sites were open and some risk assessment is being done,” said Ric McIver.

“We know there are a lot more open excavations around, but we don’t know which will manifest in sinkholes.”

The city is monitoring nine abandoned sites in Calgary and three of these sites have already had work done.

“Once problems start popping up, the city must become more aware, especially when projects are pushed back for an uncertain amount of time,” he said.

“It makes the need for due diligence greater.

McIver said the sinkhole problem is starting to become a major public policy issue in the city.

“We probably need to review our policy on open excavations and make sure we are covered in terms of the amount of time it is open, the type of shoring that is used to maintain the integrity of the surrounding area,” he said. “The review will also include what type of due diligence and inspections can be done and who would pay for it.”

Centuria on the Park broke ground a year and a half ago and is still in the excavation phase.

The discovery of the sinkhole marks the third time a hole has been found near the construction site in the past 10 months.

The first sinkhole appeared last July.

The second was found last fall on 2nd Street, between 13th and 14th avenues. It was repaired by the city’s roads department.

So far, no connection has been determined between the holes and the adjacent construction site.

This is the second time in a week that a large sinkhole has developed next to the excavated construction site of a condo development in downtown Calgary.

A massive sinkhole, which was discovered on April 24, developed under a road adjacent the Gateway-Midtown condo project, owned by Pointe of View Developments.

Its cause has not yet been determined.

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