Abstract
This paper develops a Bayesian approach for model comparison and characterization of the bivariate distribution of c′ and ϕ′ using limited site-specific data. The copula approach is presented to model the bivariate distribution of c′ and ϕ′. The Bayesian model comparison method is developed to select the most probable bivariate distribution model of c′ and ϕ′. The most probable model is used to characterize the joint probability density function (PDF) of c′ and ϕ′ under the Bayesian framework. The developed approach is illustrated and validated using real data of c′ and ϕ′ for clays from the core wall of Xiaolangdi rockfill dam in China.