RE:RE:RE:RE:Quakes - Put your money where your mouth is!
Bluesteele, you state "Hi Dave, I think you have to consider the geology of each deposit. Silt acts as a binding agent and will fill in the spaces in a matrix... in Diavik's case. Where as the glacial till at Paterson Lake comprised of a high percentage of sand will have a greater porosity and be more susceptible to hydraulic pressure." I think you really should read the Diavik construction report and details of their dike, the silt was not helpful and their glacial till was porous, but that did not stop them. They actual had to first dredge out the silt to give them a stable base to build a dam on, then they built a porous dam and once the dam was built they then scooped out right down the middle of the dam and filled it floor to ceiling with a plastic concrete impermeable barrier. The impermeable barrier meant that it made no difference that the till was permeable. Then any water getting past the barrier (none did) was to flow into a drainage system. So the fact that the till at diavik was water permeable did not stop the project.