Comparison of liquefaction triggering methods for sloping ground using two flow failures from the 2010 haiti earthquake

Evaluating liquefaction (both triggering and post-triggering) of sloping ground remains a difficult task for practicing engineers. For triggering, two approaches are available: (1) the cyclic stress method modified with corrections for high overburden stress and static shear stresses; and (2) the yield strength ratio method. Similarly, for post-triggering stability analysis, two general approaches are available to estimate the liquefied shear strength: (1) correlations for residual strength; and (2) correlations for liquefied shear strength ratio. These triggering and post-triggering methods were applied to two slope failures induced by the Mw 7.0 Haiti (2010) earthquake. The analyses suggest that the yield and liquefied strength ratio approaches provided factors of safety consistent with observed performance. In contrast, methods using the cyclic stress approach and residual shear strength provided results that were consistent with only one of the two case histories described in this paper.