Quantitative liquefaction-induced lateral spread hazard mapping

To quantitatively map regional lateral spread hazard considering a complete portfolio of possible earthquakes is fundamental for a seismic risk assessment over large spatial coverage. This paper presents a probabilistic model of liquefaction-induced lateral spread considering seismic randomness and uncertainty of soil properties. This model enables quantitative maps of lateral spread displacement at any exceedance probability in a specified time period, or exceedance probability of any pre-defined displacement threshold. Two mapping procedures are illustrated through a case study by generating hazard maps of lateral spread based on available cone penetration test data. These maps highlight the hotspots susceptible to serious lateral spread displacements, providing useful information on need of project-specific in-depth geotechnical investigation. The mapping procedure is based on either geostatistical interpolation or stochastic simulation. The geostatistical interpolation method has the merit to be less computationally expensive, while the stochastic simulation method seems more rational as it explicitly model the uncertainty of soil parameters and their spatial structure.