Dam Failure Lesson Learned: Static liquefaction should be considered as a potential failure mode for dams that have loose sands or silts in their embankments or foundations

Static liquefaction is a phenomenon in which saturated, loose sand or silt loses strength and collapses rapidly under sustained shear loading, generating high pore water pressure in the soil mass and very low strength. The stress-strain behavior is brittle, and the low residual strength is much lower than the static shear stresses, creating a large force imbalance resulting in acceleration, velocity, and flow of the soil mass. The behavior during failure is referred to as flow liquefaction. A lesson to be learned from the May 19, 2020, failure of Edenville Dam in Michigan is that static liquefaction needs to be considered as a potential failure mode for water dams that include loose sands or silts in their embankments or foundations.