Staff
The Portage Avenue underpass will continue to be completely shut down to all through traffic for the next three weeks, in order to complete the west side concrete lane slabs.
While the total closure was only expected to last for about a week, Operations and Facilities manager Doug Brown said in an e-mail late yesterday, that as a result of the excavation work over the past three days, it was determined that the existing sub-grade material contains soft silty clay with layers and pockets of silty material.
As well, the water table at the lowest point of the underpass is very close to the elevation of the top of sub-grade.
The soft silty clay has trapped water and under traffic and vibration, it will turn into a slurry mud he added.
“As a result during the preparation of this sub-grade and placement of the ensuing layer of granular ‘A’ base, the prepared surface cannot be distributed by traffic. The pumping action from the road traffic will soften the saturated sub-grade and create large wheel ruts thus if a lane was opened up it soon would be non-accessible,” he explained.
Brown noted the contractor has committed to working seven days a week in order to complete the west side concrete lane slabs.
“Basically, it is forecasted that this task should take two weeks to complete and seven days of cure time for the newly-placed concrete to gain the proper strength to support the traffic loads,” he said. “Therefore in summary, it is necessary to close the Portage Avenue underpass 24 hours a day for approximately a three week period to complete the west side concrete lane slabs. Also, it should be clearly stated that weather will have a significant impact on the progress of completing the task.”
The new west side pedestrian walkway will continue to be open at all times.
Motorists will have to keep using McIrvine Road to access the north end of town.
Emergency vehicles will have to use either McIrvine Road or the Victoria Avenue emergency railway crossing to gain access to/from the north end of the community.
The fire department will be coordinating the use of this Victoria Avenue emergency railway crossing with other emergency agencies.
