Ontario Power Generation- Dam Repair- Aecon Industrial
Market: Power Generation
Year: 2006
Owner: Ontario Power Generation
Consultant: Structural Inspections
Client: Aecon Industrial
Location(s): Deep River, ON
Contract Type: Fixed Price
Contract Value: $420,000
Project Duration: 3 Months
Project Status: Complete
Located 21 kilometers west of Deep River, ON, Des Joachim’s GS is the largest hydroelectric facility owned by Ontario Power Generation on the Ottawa River. Restoration work on the face of the dam was completed by Raven Construction in the Fall of 2006.
Raven Construction's responsibilities with respect to the dam restoration included the following:
Supply, assemble and install an engineered cofferdam system
Dewatering of cofferdam (24 hours per day, 7 days per week)
Removal of deteriorated concrete from exposed dam surface and install new reinforcing steel within dam face
Installation of 1-inch-thick steel plates at dam restoration locations. Steel plates were utilized as formwork in support of concrete placement and remained in place as the permanent face of the restored dam section
Placement of concrete at dam restoration locations
Highlights: Being located on the Ottawa River, all work taking place was environmentally sensitive. A protective curtain was installed within the river to capture silts or debris resulting from dam demolition and/or restoration activities and all dewatering had to pass through a filter bag prior to release into the river.
A diving company was subcontracted to support the installation of the cofferdam within the river. This required the cofferdam to be fastened to the surface of the dam and sealed off to mitigate the potential for river water to penetrate through the cofferdam once the dammed off section was dewatered.
The structural integrity of the dam was inspected and confirmed by a certified engineer prior to the crane walking out onto the dam in support of cofferdam installation.