PROBABILISTIC EVALUATION OF LIQUEFACTION POTENTIAL UNDER EARTHQUAKE LOADING

This paper presents a procedure to perform the risk analysis for groun d failure by liquefaction. The first part of this study describes the differential equation of a smooth hysteretic model to characterize the behavior of the soil under random loading. The parameters of the prop osed model to represent the experimental relationship are discussed. T he second part of this study is to develop a method to calculate the p robability that a specified volume of soil will liquefy at a given dep th in the deposit. The liquefaction is defined as the result of cumula tive damage caused by seismic loading. The fatigue life of soil can be determined on the basis of the N-S relationship and Miner's cumulativ e damage law. The rain-how method is used to count the number of cycle s of stress response of the soil deposit. Finally, the probability of liquefaction is obtained by integration over all the possible ground m otion and the fragility curves of liquefaction potential. The sensitiv ity of the reliability against liquefaction to soil system parameters is also examined.