The reliability of structures is dependent on the variability in random characteristics of the strong ground motion. In this paper, the influence of the variability of ground motion variables on the variability of the structural response has been accessed by sensitivity analysis. The variance-based sensitivity analysis (VBSA) is considered by using the Monte Carlo based procedure, for computing the set of first order sensitivity indices of the variables to estimate the contribution each uncertain input, makes to variance in the model output. The variables that have a dominant influence on the uncertainty of structural response are identified. The analytical results show that the formulation of dynamic structural response in frequency domain based on seismological information of the excitation can be used in some parts such as Iran with lack of recorded strong motion.
