Penetration and Liquefaction Resistances: Prior Seismic History Effects

Cyclic triaxial tests and cone penetration tests performed in large-scale triaxial samples are used to evaluate the effects of prior cyclic-strain history on the liquefaction and penetration resistances of a fine, uniformly graded sand. Prior cyclic-strain history is found to increase both liquefaction and cone-sleeve friction penetration resistance (fs), but has no significant effect on cone-tip penetration resistance (qc). This, in turn, suggests that cone-tip penetration resistance represents a somewhat conservation basis for evaluating the liquefaction resistance of sandy soils with beneficial prior cyclic-strain histories (prior seismic histories), and also has ramifications with regard to the reliability of soil classifications based in part on the ratio qc/fs in soil with prior cyclic-strain histories.