← Back to Sessions

Development of USGS Computational Tools for Long-term Forecasting of Liquefaction Ground Failure Hazards

Description: 

Long-term probabilistic liquefaction hazard forecasts provide valuable information for identifying infrastructure that is potentially vulnerable to earthquake-induced ground failure. This is most effectively achieved through probabilistic liquefaction hazard analysis (PLHA), which integrates annualized ground-shaking hazard information from all potential earthquake scenarios with probabilistic models of liquefaction limit states (e.g., triggering, surface manifestation, ground deformation). PLHA calculations typically result in annualized rates or long-term probabilities of liquefaction occurrence, which can help inform risk-based earthquake engineering assessments. Such calculations require a thorough representation of uncertainties, reflecting variability in site and groundwater conditions, and both within-model and cross-model uncertainty in liquefaction hazard estimation, and are ultimately represented via ranges and fractiles of the annualized rates of liquefaction occurrence.

We present an in-development Python library for performing PLHA calculations to estimate long-term liquefaction manifestation probabilities. We demonstrate the use of the code for a large set of cone penetrometer test (CPT) sites throughout United States. Probabilistic ground motion hazard data are obtained directly from the U.S. Geological Survey National Seismic Hazard Model and integrated with a set of published liquefaction manifestation models to ultimately estimate the annualized rate of liquefaction manifestation at a given CPT location. We incorporate uncertainties in groundwater levels and susceptibility criteria, and comparisons across multiple manifestation models, into these analyses to demonstrate the sensitivity of model assumptions to hazard estimates. Preliminary results suggest that variations in all three factors can significantly impact the estimated hazard. This computational framework represents a promising avenue towards systematic and comprehensive liquefaction hazard forecasts, both for site-specific design applications and as the basis for improved regional-scale liquefaction hazard mapping efforts.

Session: Data-Driven Advances in Liquefaction Hazard Analysis [Poster]

Type: Poster

Date: 4/17/2026

Presentation Time: 08:00 AM (local time)

Presenting Author: Andrew J. Makdisi

Student Presenter: No

Invited Presentation: 

Poster Number: 20

Authors