Correlation study between seismic acceleration parameters and damage indices of structures

This study describes numerically, the interdependency between several seismic acceleration parameters and diverse structural damage indices. Peak ground motion, spectral and energy parameters are used for characterising the seismic excitation. On the other hand both, structural and nonstructural damage is considered, expressed by the modified Park/Ang overall structural damage index (OSDI), the maximum interstory drift (ISD) and the maximum floor acceleration. After the numerical evaluation of several seismic parameters, nonlinear dynamic analyses are conducted to furnish the structural damage status. The degree of the interrelationship between the seismic parameters and the damage indices is provided by correlation coefficients. The investigation is carried out for a reinforced concrete plane frame system designed after Eurocodes 2 and 8 (EC2, EC8) and the aim is to determine the characteristics of the accelerograms that exhibit the strongest influence on structural and nonstructural damages. The numerical results have shown, that peak ground motion seismic parameters provide poor or fair correlation with the OSDI, whereas the spectral and energy parameters provide good correlation. Furthermore, the central period and the strong motion duration after Trifunac/Brady exhibit poor correlation with the OSDI. All these results give reason to recommend the spectra and energy related seismic intensity parameters as reliable descriptors of the seismic damage potential.