Posted on February 02, 2015
The failure of the Mt Polley tailings facility vindicated Karl Terzaghi and Ralph B. Peck, the two great engineers who founded the science and art of geotechnical engineering. They always warned that the undetected geological feature, stratum, or layer was the cause of failure. This is exactly what happened at the part of the embankment that failed at the Mt Polley mine—the original site investigation failed to identify or characterize a layer of glaciofluvial clay. Subsequent work failed to establish correctly the strength of the layer. And that layer failed when the load from the embankment exceeded the strength of the clay.