|CLIENT:||Vale Newfoundland and Labrador|
|CONSULTANT:||Fluor Canada Ltd.|
|CONTRACT TYPE:||Unit Price|
|Project SIZE:||150,000 cubic m. of excavation|
350,000 cubic m. of processed dam zone fills
H.J. O’Connell Construction Limited (HJOC), a subsidiary of Bird, completed the residue storage area and dams project at Vale’s Long Harbour Nickel Processing Plant substantially ahead of schedule. A 50% increase to scope due to geotechnical condition changes including lower than expected rock elevations also required additional excavation and backfill in the same time frame. The project consisted of three earth filled dams encapsulating the residue storage area. Once the plant is operational, the area will be used for the storage of tailings in the processing of nickel.
During the project, the team encountered the challenge of lowering an existing lake eight metres to facilitate excavations. HJOC tripled the dewatering rate by pumping water into an adjacent small pond and using a natural stream bed, in combination with a diversion channel, to allow the water flow to be increased without causing negative environmental impact. By increasing the drawdown rate, we were able to accelerate the project schedule.
During construction, winter weather conditions posed a threat to the schedule; however, through value engineering, HJOC altered the original design scope and positioned the first dam one metre downstream to allow the grout trench and dams to be built independent of one another, rather than dependently as originally proposed. Subsequently, the team was able to deliver the project ahead of schedule and without any lost time incidents.