Use of SPT and CPT Tests for Evaluating the Liquefaction Resistance of Sands

A cone penetration test (CPT)-liquefaction resistance relationship has been established using the large body of standard penetration test (SPT) data. Factors for relating CPT tip resistance and SPT N-values were developed for this purpose. These factors depend on the mean grain size of the material. On this basis, relationships between CPT cone tip resistance and liquefaction resistance are proposed; the resulting curves vary with the mean diameter and fines content of the material. These curves are compared with the limited available field data and satisfactory agreement is shown. The desirability of a judicious combination of CPT and SPT tests for evaluating the liquefaction resistance of any given site is suggested.