Probabilistic Standard Penetration Test-Based Liquefaction-Triggering Procedure.

A probabilistic version of the Idriss and Boulanger standard penetration test (SPT)-based liquefaction triggering correlation is derived using a maximum likelihood approach and an updated case history database. Measurement and estimation uncertainties in the cyclic stress ratio (CSR) and SPT values and the effects of the choice-based sampling bias in the case history database are taken into account. The results of sensitivity analyses show that the position of the most likely triggering curve is well constrained by the case history data and that the magnitude of the total error term is also reasonably constrained. The most likely value for the SD of the error term in the triggering correlation is, however, found to be dependent on the uncertainties assigned to the CSR and . The results of the sensitivity study appear to provide reasonable bounds on the effects of different interpretations on the positions of the triggering curves for various probabilities of liquefaction. Methods for including model and parameter uncertainties in probabilistic liquefaction analyses are briefly discussed. The derived triggering correlation is compared with relationships developed from cyclic laboratory test results for specimens obtained using frozen sampling techniques. [ABSTRACT FROM AUTHOR]