Predicting the spatial extent of liquefaction from geospatial and earthquake specific parameters

By: , and 
Edited by: George DeodatisBruce R. Ellingwood, and Dan M. Frangopol

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Abstract

The spatially extensive damage from the 2010-2011 Christchurch, New Zealand earthquake events are a reminder of the need for liquefaction hazard maps for anticipating damage from future earthquakes. Liquefaction hazard mapping as traditionally relied on detailed geologic mapping and expensive site studies. These traditional techniques are difficult to apply globally for rapid response or loss estimation. We have developed a logistic regression model to predict the probability of liquefaction occurrence in coastal sedimentary areas as a function of simple and globally available geospatial features (e.g., derived from digital elevation models) and standard earthquake-specific intensity data (e.g., peak ground acceleration). Some of the geospatial explanatory variables that we consider are taken from the hydrology community, which has a long tradition of using remotely sensed data as proxies for subsurface parameters. As a result of using high resolution, remotely-sensed, and spatially continuous data as a proxy for important subsurface parameters such as soil density and soil saturation, and by using a probabilistic modeling framework, our liquefaction model inherently includes the natural spatial variability of liquefaction occurrence and provides an estimate of spatial extent of liquefaction for a given earthquake. To provide a quantitative check on how the predicted probabilities relate to spatial extent of liquefaction, we report the frequency of observed liquefaction features within a range of predicted probabilities. The percentage of liquefaction is the areal extent of observed liquefaction within a given probability contour. The regional model and the results show that there is a strong relationship between the predicted probability and the observed percentage of liquefaction. Visual inspection of the probability contours for each event also indicates that the pattern of liquefaction is well represented by the model.

Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title Predicting the spatial extent of liquefaction from geospatial and earthquake specific parameters
Chapter 276
DOI 10.1201/b16387-299
Year Published 2014
Language English
Publisher CRC Press
Contributing office(s) Geologic Hazards Science Center
Description 8 p.
Larger Work Type Book
Larger Work Subtype Conference publication
Larger Work Title Safety, reliability, risk and life-cycle performance of structures and infrastructures: Proceedings of the 11th international conference on structural safety and reliability
First page 2055
Last page 2062
Conference Title 11th International Conference on Structural Safety and Reliability
Conference Location New York, NY
Conference Date June 16-20, 2013