Another sinkhole has developed in the College Park area of Port Moody as a result of tunnel boring for the Evergreen Line.
Amanda Farrell, the Evergreen Line project director, said the ground settled around Seaview Drive and Clarke Road, creating a five-by-five meter dip in the roadway. Seaview has been closed in one direction and tunnel boring operations have ceased until at least May, she added.
"It is difficult," she said. "We certainly didn't anticipate it happening in this location."
Farrell could not say when the road would be completely re-opened, noting that it could only happen when crews determined it was safe.
She added that at this time, the Evergreen Line is still expected to open in the fall of 2016, a timeline that had been previously delayed after earlier sinkhole issues occurred.
This week was the third time since boring began that a sinkhole has occurred as a result of the tunneling.
Last October, a depression in the road developed in the Chateau Place parking lot and in January a large sinkhole appeared on Cecile Drive.
In both cases, the sinkholes formed in areas that were already fenced off and the public was not at risk, according to the Ministry of Transportation.
One lane of Cecile Drive will remain closed with single-lane alternating traffic 24 hours a day until the work site is dismantled.
Farrell was quick to highlight some positives with the Evergreen Line construction. She noted that crews have completed more than 50% of the tunneling and that 60% of the line is compete.
The most recent sinkhole developed Thursday night, despite efforts from the contractor to build a grout wall in the ground.
Farrell said that as the boring moves up the hill and away from the water, the tunneling is expected to get easier. Geotechnical work has shown that the solid become more consistent as the move higher, she added.
Crews will continue to investigate around the perimeter of the sinkhole to ensure that the ground will remain stable as drilling continues.
"They will be doing more drilling," she said. "I would imagine that would be after they got the road back open."
