Next generation PBWE: Extension of the SAC-FEMA method to high-rise buildings under wind hazards

Abstract

This paper proposes a method for the Performance-Based Wind Engineering (PBWE) of buildings by extending the well-established SAC-FEMA method originally implemented in seismic engineering for the evaluation of the mean annual frequency (MAF) of pertinent structural Limit States (LSs) in frame buildings. The development of such a method, that we will call the “SAC-FEMA WIND” method, implies the consideration of specific wind engineering peculiarities, like the classification of the across-wind response in two distinct regimes due to buffeting and vortex shedding phenomena, with the consequent adaption of the analysis procedures already defined for earthquakes to these two regimes. The method is then applied for the MAF evaluation of the occupants’ comfort LS for a high-rise steel building: the SAC-FEMA WIND is calibrated by comparing the obtained results with those coming from a Monte Carlo numerical analysis. This allows the definition of appropriate analysis procedures and shows the reliability of the SAC-FEMA WIND in evaluating MAFs. The SAC-FEMA WIND can be viewed as a “next generation” method for PBWE, in the sense that, after years of developments of the PBWE in research, now simplified methods like the SAC-FEMA WIND are needed for the implementation in Standards and in the design practice of explicit probabilistic PBWE approaches.