09 Jun Seismic Upgrade of the Ruskin Dam Spillway Gates control Cabinets
Ruskin Dam is located on the Stave River and is the most downstream facility in the Alouette-Stave-Ruskin hydroelectric system in British Columbia, Canada. Water from the 90-MW Stave Falls Generating Station flows into Hayward Lake, a 6-km-long reservoir impounded by Ruskin Dam. The 105-MW Ruskin Generating Station is located below the left abutment of Ruskin Dam, and water discharged from the Ruskin powerhouse and spillway flows into the lower Stave River. The confluence of the lower Stave River and the Fraser River is located approximately 3 km further downstream. Completed in 1930, the dam is a concrete gravity structure composed of eight monoliths situated in a narrow valley and founded predominantly on bedrock.
In 1961, when the provincial government took over the BC Electric Company, the dam became the property of BC Hydro, a Crown Corporation. The Ruskin Dam Safety Project was initiated in 2007 to review and address the dam safety issues associated with the concrete dam and right abutment and includes:
- Reinforcement of the right abutment
- Seismic upgrade of the dam and water intakes
- Powerhouse upgrades
- Relocation of the switchyard
A 3D Isolation system was used to seismically upgrade the spillway gates control buildings and critical equipment to protect against horizontal accelerations during a seismic event. In the Ruskin Dam application there were significant vertical accelerations. Therefore the Isolation System has to be able to decouple all 3-axes to avoid damaging accelerations in both horizontal (X,Y) and vertical (Z) directions.
Overall the spectral accelerations were reduced by a factor of 18 and were required to meet IEEE 693 High Performance code requirements.