Dam Liner for White River Dams
The White River Dams hydro project included building two dam liners. Located on the White River, the hydro project is approximately 50km south of the town of White River in Northern Ontario, Canada. A joint venture between Regional Power and Pic Mobert First Nation, construction began in August 2013 and is expected to continue through 2016. There are two separate hydro generation sites Gitchi Animki Bezhig (Upper) and Gitchi Animki Niizh (Lower) located 10km from each other, both are ‘greenfield’ projects.
The dam liner was designed to be a free-standing low-permeability wall, laid on a concrete foundation tied to the riverbed, held inside a plinth of compacted rock and gravel. Challenges with coating and sealing to achieve the required low permeability excluded conventional steel sheet piles in favor of composite. Wolf Remediation Ltd composite sheet pile solution was also favorable when compared on cost over the expected 50 – 70 year lifespan of the dam liner.
With hydraulic head of 14 meters in the Upper Dam, standard 35-foot composite sheet piles were used, joined with hand-applied hydrophilic sealant, to achieve a permeability of no less than 10-11.
The Lower Dam, with a hydraulic head of 21 meters, required a dam liner 72-foot in height. With the longest composite sheet available being 52-foot, Wolf Remediation Ltd designed, tested and built an H-Clip to join sheets vertically, extending the wall to the required height.
To support the extended sheets while being installed, Wolf Remediation Ltd project lead designed a tailored framing solution of soldier piles and whalers.
The stainless steel prototype H-Clip (patent pending) took six weeks to develop and test. The testing apparatus allowed the H-Clip between two sections of 4’ composite sheet pile to place a force downwards to create 2” of deflection while underwater, with 20lbs psi. MWH Global Engineering Vancouver office approved the testing criteria and results.
Wolf Remediation Ltd was able to test their sealing techniques in the joints of the sheets to allow for 70’ of head pressure on the upstream side of the Dam wall. This testing was done with pressure of up to 110lbs psi with no leakage.
Wolf Remediation Ltd composite sheet pile solutions offer an alternative to conventional materials and have a wide range of uses. With a high strength to low weight ratio, composite sheet piling affords easier handling, more economical shipping, lower maintenance on installation, and a longer life-span. An environmentally sensitive solution with no compromise.