Seismically-induced liquefaction has been the cause of significant damage to infrastructure and is a serious concern in current civil engineering practice. Several methods are available for assessing the risk of liquefaction at a given site, each with its own strengths and limitations. One probabilistic method has been shown to provide more consistent estimates of liquefaction risk and can be tailored to the specific needs of a given project through hazard-targeted (i.e. based on return periods or likelihoods) results. This type of liquefaction assessment is typically called “performance-based,” after the Pacific Earthquake Engineering Research (PEER) Center's performance-based earthquake engineering framework. Unfortunately, performance-based liquefaction assessment is not easily performed and can be difficult for practicing engineers to use on routine projects. Previous research has shown that performance-based methods of liquefaction assessment can be simplified into an approximation procedure. This simplification has successfully been completed for the Cetin et al. (2004) empirical, probabilistic standard penetration test -based liquefaction triggering model. Until now, such a simplification has not been performed for another popular liquefaction triggering model developed by Boulanger and Idriss (2012). As some engineers either wish to use or are required to use the Boulanger and Idriss (2012) model in their liquefaction assessments, there is a need for a simplified performance-based method based on this model to supplement that based on the Cetin et al. (2004) model. This thesis provides the derivation of a simplified performance-based procedure for the assessment of liquefaction triggering using the Boulanger and Idriss (2012) model. A validation study is performed in which 10 cities across the United States are analyzed using both the simplified procedure and the full performance-based procedure. A comparison of the results from these two analyses shows that the simplified procedure provides a reasonable approximation of the full performance-based procedure. This thesis also describes the development of liquefaction loading maps for six states and a spreadsheet that performs the necessary correction calculations for the simplified method.



College and Department

Ira A. Fulton College of Engineering and Technology; Civil and Environmental Engineering



Date Submitted


Document Type





liquefaction, performance-based earthquake engineering, PBEE, probabilistic, standard penetration test, SPT, probability of liquefaction, map-based procedures