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Thump, thump goes the pile driving
The ongoing thud of pile driving in Coquitlam City Centre will continue for a few more years, city council heard last week.
Besides the spurt of highrises going up, pile driving will also be needed down Pinetree Way to support Evergreen Line columns and stations, said Maurice Gravelle, the city's strategic initiatives general manager.
The issue of pile driving came before council-in-committee on July 15 when building permits manager Doug Vance spoke about the number of complaints the city receives and its attempts to lessen the hammering.
In July 2010, council changed the noise bylaw to allow pile driving on Saturdays from 9 a.m. to 5 p.m. instead of 7 a.m. to 10 p.m. to respond to residents' and business owners' concerns. As well, the city hired a geotechnical engineer to consider alternate pile driving technologies.
In the City Centre, pile driving is required in some areas — such as along Pinetree — to lay a deeper foundation; however, three blocks away, pile driving may not be needed because of the different soil conditions.
For example, at 1123 Westwood St., where Onni plans a 33-storey tower, the company will be using spread footings and raft slabs; at other sites, such as at Cressey's M2, a preloading of the property will be enough while pile driving will be required for its 44-storey M3 project at 1188 Pinetree Way.
Vance said city building permits staff have been meeting early with developers and contractors to find ways to mitigate the pounding.
Recently, Bosa used sound-dampening pads for two test piles at 3007 Glen Dr. but the difference was only five decibels, he said. However, through a reassessment, Bosa has concluded it will need 20% less piles for its site, Vance said.
Vance recommended council not regulate the type of technology used by designers. If it interferes, he suggested, it could open the city to liability in the event of building failure.
He said one solution is for the developers and contractors to communicate better about the construction schedule, and have a liaison available to answer any pile driving concerns.
Mayor Richard Stewart said City Centre will face growing pains for many years. "Our City Centre is going to be magnificent but these are the early days and there will be challenges," he said.