Liquefaction potential index considering parameter uncertainties

Liquefaction potential index is frequently used to assess the liquefaction susceptibility of soils. While calculating the liquefaction potential index, factor of safety is integrated over depth with a weighting function. No-liquefaction is assumed if the calculated factor of safety is greater than one. Due to soil variability and model parameter uncertainties, even a factor of safety greater than one does not confirm the safety against soil liquefaction and thus the conventional factor of safety should be calibrated. In this paper, a reliability based design safety factor that considers uncertainties in model parameters is used to obtain the liquefaction potential index. A standard penetration test based simplified procedure is used to obtain the conventional factor of safety and first order reliability method is applied to obtain the reliability based design safety factor. Based on the results, it is concluded that the liquefaction potential index of the soil increases considerably with an increase in variability of model parameters, increasing the probability of soil liquefaction.