Resistance to Liquefaction Due to Sustained Pressure

It has long been recognized that clays increase in strength with time due to consolidation and secondary compression; however, the fact that sands can increase in strength after periods of sustained loading is not so well known. Recently several engineers have suggested that the liquefaction characteristics of in-situ sand deposits are influenced by the age of the deposit. Omote and Myamura presented data that showed a trend for less damage occurring in older sandy deposits during the Tokaido earthquake of December 7, 1944, and Casagrande has stated that, whenever possible, the age of a sand strata should be determined, since there are indications that young alluvial sands are much more susceptible to liquefaction than older sediments.