Calibration of liquefaction potential index: A re-visit focusing on a new CPTU model

This paper presents a review of the state-of-the-art of Liquefaction Potential Index (LPI), a parameter created by Iwasaki and his co-workers to characterize the potential for surface manifestation of liquefaction, and the results of an extensive calibration of the LPI with a focus on a new model based on piezocone testing (CPTU). The results show that the threshold criteria developed by Iwasaki and his co-workers for interpreting the calculated LPI are not universally applicable. To the contrary, the LPI must be re-calibrated when any component model of the LPI framework is replaced with a new model. The new CPTU model is a significant advance in the cone penetration-based liquefaction evaluation; in fact, it is the first simplified model that explicitly incorporates pore pressure measurement as one of its input parameters. This CPTU model is applicable to a wide range of soil types and thusly enables a more convenient and effective modeling of liquefaction effects within the LPI framework. Probabilistic characterization of the new CPTU model is carried out. Finally, the results of the calibration of the LPI calculated with this CPTU model, along with the concept of the probability of surface manifestations, are presented and discussed.