Comparison between energy and stress based pore pressure methods in liquefiable deposits

In order to mitigate the damaged induced by liquefaction events, it is imperative to evaluate the liquefaction susceptibility. Liquefaction susceptibility can either be evaluated through the retrival and testing of intact soil samples, or through procedures based on in-situ tests. Both of these frameworks are based on equivalent stress cycles (or stress-based methods), however, other types of methods (strain based or energy based) were developed with different base principles but with the same objective of predicting liquefaction triggering. In this paper the updated version of the stress based method will be compared with a dissipated energy based method, discussing their main advantages and limitations. For that purpose, nonlinear dynamic effective stress analysis were performed using the commercial software FLAC® using PM4Sand as the selected constitutive model. Using a database of 500 numerical analysis, the liquefaction triggering obtained in both simplified methods was compared with liquefaction triggering obtained in the numerical analysis. The results show that the simplified methods tend to overpredict liquefaction in comparison with the numerical analysis