A liquefaction criterion based on field performances around seismograph stations

A criterion is presented for assessing the liquefaction potential of a soil deposit to earthquake motions. The criterion, originally developed in 1970 by one of the authors, uses three basic factors: (1) soil type, (2) standard penetration test (SPT) N-value around the water table, and (3) maximum acceleration at the ground surface. By replacing the second and third factors with a normalized SPT N-value (corrected for the specified effective vertical stress) and shear stress ratio (earthquake-induced shear stress divided by vertical effective stress), an extended criterion is obtained. The applicability of the extended criterion is examined with the field performance data obtained at and within 5 km from the strong-motion observation stations.