On the spatial variability of CPT-based geotechnical parameters for regional liquefaction evaluation

•Multiscale random filed-based method for regional liquefaction mapping is proposed.•Different approaches are developed for CPT spatial variability.•Qualitatively consistent results with manifestations are obtained.•Averaged index approach is recommended for regional liquefaction evaluation.

In-situ index tests, such as the cone penetration test (CPT), are widely used for the site-specific evaluation of liquefaction potential and are getting increased use in the regional mapping of liquefaction hazards. In this work, the spatial variability of CPT-based geotechnical parameters on the liquefaction potential evaluation is assessed through an integrated framework combining an empirical liquefaction model and a multiscale random field model that allows the effective incorporation of soil spatial variability across scales. Within this framework, two approaches, termed the local soil property approach and the averaged index approach, are developed and assessed for the characterization of spatial variability in CPT-based geotechnical parameters. The proposed framework is applied to the probabilistic and spatial assessment of the liquefaction potential of an earthquake-prone region to demonstrate its applicability and to investigate the implications of spatial variability on regional liquefaction susceptibility evaluation.