Next Generation Liquefaction (NGL) Overview

The Pacific Earthquake Engineering Research (PEER) Center initiated the Next-Generation Liquefaction (NGL) project in 2013 with the objective of organizing research in soil liquefaction and related topics into a framework conducive to broad data dissemination and development of improved procedures for modeling of liquefaction susceptibility, triggering, and various effects. The U.S. Nuclear Regulatory Commission (NRC) and the U.S. Bureau of Reclamation (USBR) have identified the need to update existing regulatory guidance on the methods used to evaluate seismic soil liquefaction and have contracted the Center for Nuclear Waste Regulatory Analyses (CNWRA®) to work with NGL to achieve common goals. The collective suite of predictive models should quantify aleatory variability in predicted outcomes (e.g., susceptibility, triggering, or deformations), fully capture epistemic uncertainty, and operate over the parameter space of engineering interest. To meet this objective, the NGL project is organized into three activities: (i) develop a community-based case history database that documents ground failures and non-failures from seismically-induced liquefaction, including the associated seismic, geological, and geotechnical information as well as data from laboratory experiments; (ii) conduct supporting studies to augment case history data for conditions that are influential to predicted outcomes but that are poorly represented in empirical databases; and (iii) provide an open, collaborative process for model development in which developer teams have access to common resources and share ideas and results during model development to reduce the potential for mistakes and to mutually benefit from best practices.