Assessment of the Statistical Distributions of Structural Demand Under Earthquake Loading

Many existing probabilistic seismic safety assessment studies assume that structural demand conditional to a seismic intensity follows a lognormal distribution. Based on the analysis of five reinforced concrete structures subjected to real earthquake records scaled to several intensities, an in-depth analysis of this assumption is performed using adequate statistical methods. The considered demand parameters are the chord rotation, curvature, shear force, and inter-story drift. The results found indicate that the lognormal distribution is suitable for the probabilistic modeling of the considered demand parameters. In addition, the normal distribution was also found suitable for the shear force demand.