SPT-based probabilistic evaluation of soil liquefaction potential considering design life of civil infrastructures

Abstract

The standard penetration test (SPT) is commonly used in the simplified liquefaction triggering procedure for assessing soil liquefaction potential. However, liquefaction assessment results evaluated from limited SPTs contain significant uncertainties. Moreover, the design levels of seismic ground motion, a key input to the SPT-based liquefaction triggering procedure, depend on the design life of a given structure. Thus, disregarding the above-mentioned uncertainties and the design life of a structure can lead to biased liquefaction assessment results and pose a significant risk to civil structures. To tackle this challenge, this study proposes a fully probabilistic framework for delineating the spatial distribution of soil liquefaction potential in a vertical cross-section of a specific site over the target structure design life (e.g., 50 years). The method is used to analyze real data from the Wildlife Liquefaction Array, USA, and demonstrates its ability to capture the spatial distribution of liquefaction potential and quantify the liquefaction probability at each point of a cross section. A sensitivity study is also performed and shows that the liquefaction probability of the cross-section increases with the target design life of the structure. These results provide practitioners with valuable information for accurate assessment and effective mitigation of liquefaction risk.