Characterizing the Liquefaction Resistance of Aged Soils

The occurrence of liquefaction in soils is often evaluated using the simplified procedure originally proposed by Seed and Idriss based on in situ indices. Although numerous studies have been conducted to improve and extend this procedure, the effect of age on liquefaction resistance is still poorly understood and correction factors have not been generally accepted. Nine published studies on the effect of age are reviewed in this paper. A regression line representing the average variation in liquefaction strength grain with time was developed from cases where strength was expressed based on recommended liquefaction resistance curves. This regression line is considered an update of the previously proposed relationship by Arango et al. The results indicate that commonly used liquefaction evaluation procedures can be overly conservative in many natural soil deposits.