Tension crack on north bank of Site C dam site
BC Hydro and its contractor are starting remediation work on the 400-metre tension crack on the north bank of the Site C dam site.
A two-stage remediation plan will begin today with the construction of a toe berm to hold the area stable. This work is expected to be completed in late March.
Completion of the toe berm will allow a second stage of the remediation to focus on safely removing the material from the north bank and allowing work to resume.
Safety is our top priority. Over the past week, BC Hydro’s design and safety teams and technical experts in slope stability have been undertaking geotechnical assessments. Monitoring instruments, including survey prisms and inclinometers, have shown that the slope around the crack is stable. In addition, drilling equipment was used to drill and install additional instruments to gain a more detailed understanding of the crack, which informed the remediation plan.
BC Hydro expects to complete the remediation work for the tension crack within the overall project budget and schedule.
As part of Site C construction, work has been underway for the past 19 months to remove unstable soil to create stable slopes for eventual dam construction. During the construction of a haul road to support this excavation work, a tension crack appeared. Tension cracks are not unexpected in this area; however, this particular crack requires attention due to its significant 400-metre length.
While there was some initial movement of soil, it has now stabilized. This area of unstable soil was already slated to be removed as part of engineering new stable banks for dam construction.
Additional Information:
Information Sheet: North Bank Slope Stabilization [PDF, 191 KB]
Contact:
BC Hydro Media Relations
p. 604 928 6468