Investigation Correlations between Strong-motion Duration and Structural Damage

Abstract

A number of studies have been conducted on the investigation of the effects of the strong-motion duration on structural damage. However the conclusions from these studies are very contradictory. Some studies report significant effects while others report minimal or no effects. The objective of this study is to investigate the correlations between the duration of earthquake strong motion and the structural damage. For the purpose of this study, three reinforced concrete frame buildings (4-, 10-, and 16-storey) were designed according to the 2005 Edition of the National Building Code of Canada. The buildings were assumed to be in Vancouver which is in a high seismic zone in Canada. Nonlinear time-history analyses were conducted on the three buildings using 40 simulated accelerograms representative of the characteristics of ground motions in Vancouver as seismic excitations. The ground motions were scaled to the spectral acceleration at the dominant period of the building. Different definitions of strong-motion duration are considered in the study including uniform duration, bracketed duration, significant duration, and effective duration. The structural damage is represented by interstorey drift, column ductility, beam ductility, and base shear. Based on the results from the study, it was found that there is no correlation between the strong-motion duration and the structural damage.