Probability modelling of shear strength parameters of RCC gravity dams for reliability analysis of structural safety

Modelling concrete shear strength is the main difficulty in probabilistic reliability analysis of gravity dam structural safety. The main reason arises from the lack of test data on the parameters. This paper proposes a procedure for probability modelling of Roller Compacted Concrete (RCC) gravity dam shear strength based on all tests performed during dam construction and all available data. The procedure embraces several methods: statistical analysis of RCC density, analysis of scatter at different spatial scales, data unification, and a physical formulation of the RCC intrinsic curve. A case study demonstrates the applicability of the procedure on an existing RCC gravity dam. The probability distributions obtained are incorporated into the formulation of the shear strength limit state using a first order reliability method and Monte Carlo simulations.