Global sensitivity analysis of concrete gravity dams subjected to seismic excitation

In this study, global sensitivity analysis is performed to determine relative importance of random variables and their interaction effects onto the response of concrete gravity dam model. The dam-foundation reservoir system is considered in this research to investigate the effect of input variables in the mentioned system. Material properties of concrete and foundation are assumed as random variables to tackle epistemic randomness involved in these models. The main novelty of this paper is to quantify the effect of each uncertain input variable and its interactions with other variables on the response of gravity dams. Most of the studies in the field of dam engineering focused on parametric or local sensitivity approaches. Nonetheless, these methods have the following drawbacks. First, they are based on only one point in the variable space. Second, the interaction between uncertain variables cannot be determined in parametric and local sensitivity analyses. On the other hand, in global sensitivity analysis, the interactions of random variable with other random variable are determined over the whole input space. In this research, variance-based sensitivity analysis is utilized as the model free global sensitivity approach to accurately quantify the effect of each random variables in the response of concrete gravity dams.