Thread by @Lidsville

This morning, the civil/mechanical engineer has some further worries about #SiteC re: its design. I'll screenshot what he wrote (you can also read it in the Alt text).

His remarks arose from seeing this recent #SiteC construction photo from @BCHydro. Site diagram for reference.

@bchydro We invite anyone from @bchydro to respond to this civil engineer's concerns. Too many engineering/ construction experts have raised red flags about #SiteC's safety. The dam has already failed during construction so their fears are built on facts more solid than the dam. #bcpoli

@bchydro A few further remarks from an engineer: "Another thing we don't know is how on earth they'll attach the earthfill dam to the concrete on the north and south ends, esp the south side against the buttress. These are both shear connections... with soft banks..."

@bchydro Engineer: "In the past we've covered the concern of water percolating under the dam through fissures and bedding planes. These can't be calculated using permeability tests when dealing with shale that reverts to mud in water...."

@bchydro ....."This is a time dependant problem and won't occur initially, but is an ongoing concern. Water coming out downstream under the dam can start erosion back into the dam, eventually leading to failure if not prevented in the initial design and construction." //

@bchydro With an L-shaped dam, how do you join the 2 pieces at the 90 degree angle? That's the big question. And we don't know what BC Hydro has planned to secure that corner, but this has never been tried with a major earthfill dam anywhere in the world AFAIK.

https://twitter.com/Lidsville/status/1550547601275043840

@bchydro Asked the engineer if he knew what method BC Hydro will use to securely attach the 2 arms of the L of the L-shaped #SiteC dam. Surely #SiteC's designers understand the unimaginably large forces that the volume of reservoir water in a dam exerts, and yet...

He says:
#bcpoli