Numerical and comparative study of earthquake intensity indices in seismic analysis

Abstract

Elastoplastic and time-dependent analysis of seismic structures has become a major analysis technique in popularly accepted performance-based seismic design. However, the primary diffi culty in using this technique is the lack of a unifi ed criterion in the selection of various intensity indices of ground motions. Various earthquake factors infl uencing the elastoplastic response of seismic structures are highly sophisticated. Hence, it is vitally important to choose an appropriate and comprehensive earthquake intensity index to achieve an accurate correlation with the structural performance. In this study, a total of 30 earthquake intensity indices published in the literature are reviewed and are evaluated through correlation analysis based on 60 ground motion records. Examined herein is the correlation between existing earthquake intensity indices and the seismic responses of elastoplastic single degree-of-freedom and multi degree-of-freedom systems. The characteristics and applicability of such indices are also discussed in some detail, based on which appropriate earthquake intensity indices are recommended.