Intensity measures for the seismic response prediction of mid-rise buildings with hysteretic dampers

Dampers are energy-dissipating devices widely applied for new and existing structures in earthquake prone areas. Among the different types of devices, hysteretic dampers are particularly popular due to their simplicity, economy and low cost. Although many studies have focused on ordinary buildings for evaluating the predictive capability of the different intensity measures (IMs), those dedicated to structures with dampers are scarce. The objective of this paper is to evaluate the capability of the most commonly used IMs to predict the seismic response of frame structures with hysteretic dampers, having low-to-moderate height (less than about 12 stories) and low height-to-width aspect ratios (less than approximately 3). To this end, a 6-story reinforced concrete (RC) frame structure designed to fulfill the old Italian seismic codes was retrofitted with hysteretic dampers. The dampers were designed for two different scenarios depending on the distance to the fault (i.e. near and far field ground motions). Two sets of accelerograms, consisting of ordinary and pulse-like near-fault records, are used in the analyses. Modified versions of existing IMs are also proposed, with the intention of improving the correlations between the considered IMs and response quantities.