Port Mann bridge will be blasted…when it suits local shoals.
The ongoing demolition of the 50-year-old Port Mann Bridge, the old-timer that lies adjacent to its shiny new sibling, is moving forward.
“We need to remove the eight in-water bridge pedestals. Seven will be demolished by explosives, one will be cut into pieces,” said Greg Johnson, spokesman for Transportation Investment Corporation, the provincial agency responsible for the $3.3 billion Port Mann-Highway 1 project.
Demolition of the old Port Mann Bridge is required in order to complete construction of the new bridge to its full 10-lane width. The process is complicated – dismantling is a more accurate description of what’s involved – and requires removal of the bridge’s superstructure, substructure, piers and footings down to the Fraser River.
Because the Fraser River under the bridge is a sensitive fish habitat and fish transit area from the beginning of March until June, no on-water bridge work takes place during that time of year.
“There were two blasts in early February 2014 and the next five explosions will take place during the low-risk window for fish, which resumes in June,” Johnson said. “There will be a total of seven blasts and they will all be timed around the fish window.”
In order to minimize the disturbance to the fish, controlled blasts will take place at slack tide, when there is no tidal movement in either direction in the river.
“We set off small blasts in advance to scare the fish out of the area and then use the smallest charges possible,” Johnson said. “And, we wrap bubble curtains around the pedestals, in order to minimize the effect of the blasts.”
Demolition of the original Port Mann Bridge began in December 2012.
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