The purpose of this project was to design and install a ventilation access shaft through a sand and gravel esker. The seat of the cofferdam was installed 2.5m into hard rock (Schist). The operations were made increasingly difficult by boulders and high volume water flow from the surrounding Opapimiskan Lake. A vent access shaft was blasted approximately 800 feet below the cofferdam into solid rock.
The vent plenum cofferdam was added on to the design due to ground conditions being so unfavourable that excavation for construction was not feasible. Foundation piles were added into the structures shear walls to anchor them down. These were added to help with wind loading due to unsuitable ground conditions.
|Owner:||Goldcorp Canada Ltd|
|916mm Ø pipe piles, 13m deep #2 Shaft cofferdam||60 each|
|916mm Ø pipe piles, 13m deep Vent plenum cofferdam||37 each|
|916mm Ø pipe piles, 13m deep Vent plenum foundation piles||39 each|