An experimental study was performed to address the roles played by nonplastic fines in liquefaction resistance from the point view of the energy principle. The experimental study includes 45 cyclic torsional shear tests on samples with fines content from 0-45%. The experimental results were examined in terms of void ratio, relative density, and sand skeleton void ratio, respectively. It has been seen that the presence of fines content alters the roles played by void ratio or relative density to the liquefaction resistance for the soils with a fair amount of fines. For such soils, void ratio or relative density is not an effective index to liquefaction resistance. Instead, sand skeleton void ratio or intergranular relative density was proved to be a better index to liquefaction resistance. Based on the experimental results, a regression equation correlating the cumulative unit energy with effective confining pressure and intergranular relative density was also developed.
