Deterministic and Probabilistic Measures of Liquefaction Susceptibility: A Comparison

This paper aims to assess the various deterministic methods of liquefaction evaluation and compare them with probabilistic approaches in saturated silty sands. Deterministic liquefaction evaluating approaches as per Indian and European standard guidelines, and Boulanger and Idriss method are considered for the present study. Probabilistic liquefaction evaluation is carried out using Monte Carlo simulation (MCS) technique and preliminary estimation of the probability of liquefaction as per literature. Among the three deterministic approaches, Boulanger and Idriss approach gives more appropriate results as it is based on updated case histories and knowledge dataset. Probability approach by MCS technique gives more information about the liquefaction susceptibility as it considers uncertainty in the calculation of both cyclic resistance ratio and cyclic stress ratio. It can be concluded that even though, the deterministic approaches yield similar factors of safety for different boreholes at different depths, probabilities of failure values may be different.