Alternative Model for Dam Concrete–Rock Foundation Interface Shear Strength Estimation

The Barton-Choubey method is used to estimate the shear strength of rock joints based on their roughness, material properties, and stress state. It was proposed by N. Barton and V. Choubey (1977) and is widely used in rock mechanics. This paper discusses the application of the Barton-Choubey method in two-dimensional concrete gravity dam analysis of sliding stability on a concrete–bedrock foundation interface. It discusses the nonlinearity of the Barton-Choubey shear strength envelope as compared to the linear strength envelope using the conventional Mohr-Coulomb method as well as field and laboratory measurements of key variables for use in the governing equation (Equation 1). After discussing the method and measurement of input data, the paper describes how this method has been applied at selected hydroelectric concrete gravity dams in the portfolio of Erie Boulevard Hydropower, L.P. (Erie), a subsidiary of Brookfield Renewable, N.A.. These dams are private sector owned and federally regulated. Last, some recommendations for use and suggested further research are presented.