In situ liquefaction resistance of sands

There are two approaches in present engineering practice for evaluating liquefaction potential of sands (I) by "Simplified Procedure" (Seed and Idriss 1971), and (2) analysis based upon SPT tests, "Liquefaction Assessment Chart" by Seed et al., (1985). In the later, the effect of soil properties which have significant influences on the liquefaction potential of sands and cannot be studied in the lab e.g, previous strain history, aging, soil fabric, Overconsolidation ratio (OCR) and Cementation is included. By comparing the liquefaction resistance of sand by the above 2-methods, the effect of above variables has been studied on 24 sites with 92 soil profiles of sandy deposits where earthquakes have occurred. It has not been possible to isolate the effect of each of the five variables because of lack of adequate field data.