Random Response Spectrum Analysis of Gravity Dam Classes: Simplified, Practical, and Fast Approach

The seismic risk of concrete dams may be assessed using various numerical techniques, ranging from simplified methods to linear and nonlinear ones. Such methods should be combined with probabilistic concepts to account for the randomness in both demand and capacity. This paper proposes a random version of a simplified response spectrum method (involving equivalent static lateral forces [ESLFs]) for gravity dams by means of propagating uncertainties through the input parameters. Input parameter sensitivity is quantified and the extended procedure is explained step by step. Results are then generalized for the different dam classes. The impacts of sampling size and technique (i.e., pseudo-random and quasi-random) are also discussed. A time-based performance is evaluated and fragility curves are derived. This method may be used during the initial stages of a design process or safety analysis for existing dams.