Liquefaction resistance using CPT and field case histories

Relationships between cone penetration tip resistance and the liquefaction potential of sandy soils are presented to facilitate use of the cone penetration test (CPT) in liquefaction assessments. The relationships are based on 180 liquefaction and nonliquefaction field case histories where CPTs were performed and illustrate the importance of median grain size and fines content on liquefaction resistance. The proposed CPT-based relationships were developed to describe the field case histories where CPT data are available, and eliminate the need to rely on conversions of standard penetration test (SPT) blow counts to CPT tip resistance used by existing CPT liquefaction-potential relationships. A new conversion between CPT tip resistance and SPT blow count is also proposed using the liquefaction-potential relationships developed from CPT data and existing liquefaction-potential relationships developed from SPT data. Finally, tentative CPTbased liquefaction-potential relationships are proposed for clean and silty gravel based on 18 liquefaction and nonliquefaction case histories.