Lifetime risk-based seismic performance assessment of buildings equipped with supplemental damping and base isolation systems under probable mainshock-aftershock scenarios

Abstract

This research attempts to investigate the efficacy of different passive vibration control systems, from both technical and economic points of view, to mitigate the lifetime seismic risk of typical buildings under probable mainshock-aftershocks sequences via a novel probabilistic framework. In this regard, three separate common building models are considered, including 5-, 10-, and 15-story intermediate steel moment-resisting frame buildings. These models are designed optimally with/without passive vibration control systems, including hysteretic damping, linear viscous damping, and base isolation systems as independent alternatives. Next, for the hazard modeling, all active faults located in the greater Tehran area are taken into account to simulate the earthquake scenario. Afterward, probable earthquake scenarios during the 50 years of buildings’ life-spans are generated randomly, including the events, as well as their corresponding synthetic stochastic accelerograms. In the next step, responses of buildings and their cumulative losses are calculated under the whole scenarios considering various damage types such as structural, non-structural, and content-related. In the end, by using the Monte-Carlo simulation method, the seismic risk of different building alternatives is estimated. Interestingly, the application of each of the considered vibration control devices leads to a significant reduction in lifetime losses (both physical and economic). It is revealed that the viscous damper has the highest efficacy among different systems. Importantly, by neglecting aftershocks' effects, the estimated lifetime risk will be underestimated by about 27 to 57% below the expected value. Finally, among the active faults in the greater area of Tehran, the North Tehran, Kahrizak, and Mosha faults have the highest contribution in the estimated lifetime risk of buildings.