CPT Prediction of Liquefaction Resistance Using the CPT Soil Characterization Curve Lookup Technique

The author has published specialized techniques to interpret cone penetrometer test (CPT) data for prediction of liquefaction for over 30 years, starting in 1984. These techniques have been updated numerous times, most recently in 2015. In all these cases, the technique generated contours of liquefaction resistance ratio on the CPT soil characterization chart using field and laboratory data. The problem is that the shapes of these contours are always too difficult to represent by even the most complex of equations. The author has developed software to predict liquefaction resistance using this approach, and this technique has been verified by other researchers using point-to-point data comparisons. This update reflects important observations made in the last three years. The approach indirectly accounts for all soil types and relative strength consistencies without requiring the equivalent clean sand approach.