Abstract: Reliability theory is introduced to liquefaction probability evaluation for a horizontal site.Based on the statistic analysis of standard penetration test(SPT) data,a model for evaluation of site liquefaction probability is developed using the method of First-Order Second-Moment(FOSM).The relationship between the variation coefficient of test data and the factor of safety against liquefaction and liquefaction probability is analyzed,and liquefaction probability evaluation standard for a horizont...