Deterministic vs probabilistic liquefaction assessment – a case study

Deterministic seismic liquefaction assessments are often based on conservative assumptions regarding both the induced cyclic stresses and the potential earthquake magnitudes that contribute to hazard. The main limitations of the “simplified” approach are: (1) induced stresses computed using a simplified method; (2) earthquake defined in terms of single PGA and magnitude; and (3) soil resistance estimated from uncertain correlations. In reality, induced stresses strongly depend on soil properties and induced accelerations could be caused by different magnitude events. Furthermore, dealing with uncertainty in a deterministic manner can lead to additional conservatism.