Probabilistic Liquefaction Hazard Mapping

Abstract

Many investigators have applied the liquefaction potential index (LPI) to map regional liquefaction hazard. LPI, which integrates the liquefaction potential of susceptible soil elements at a specific location into a single value, has been used to assess both (1) spatial variability of liquefaction potential, and (2) liquefaction potential of surficial geologic units. A promising application to mapping has been the establishment of a median threshold LPI value at which liquefaction effects occur. This threshold when applied to complementary cumulative frequency distributions of LPI for spatially homogeneous surficial geologic units yield liquefaction probability curves for surficial geologic units that can be used for hazard mapping. Both probabilistic liquefaction scenario maps and PSHA-based liquefaction hazard maps have been produced with this approach. The scenario maps compare favorably with historical liquefaction in the mapped areas.