Probabilistic version of the Robertson and Wride method for liquefaction evaluation: development and application

Abstract

The Robertson and Wride method is the most widely used cone penetration test (CPT)-based method for soil liquefaction evaluation. This method is a deterministic model, which expresses liquefaction potential in terms of factor of safety. On many occasions, there is a need to express the liquefaction potential in terms of liquefaction probability. Although several probabilistic models are available in the literature, there is an advantage having a probabilistic version of the Robertson and Wride method so that the engineer who prefers to use this method can obtain additional information of liquefaction probability with minimal extra effort. In this paper, a simple model is developed, which links the factor of safety determined by the Robertson and Wride method to the liquefaction probability. The model, referred to as the probabilistic RW model, is developed, and verified, in a mathematically rigorous manner. Simplified equations for assessing the variation of liquefaction probability caused by the uncertainty in input parameters are also developed. Example applications are presented to demonstrate the developed models.