Performance-based Aeolian risk assessment and reduction for tall buildings

Abstract

The design of tall buildings subject to wind actions can be developed in the framework of Performance-Based Wind Engineering (PBWE). The structural performances are described by a set of measurable attributes, the decision variables, which are functionally related to proper measures of the structural damage, in turn dependent on proper engineering demand parameters characterizing the structural response, and measures of the intensity of the wind field. In this paper, PBWE is applied to the assessment of the comfort requirement and the structural reliability for a 74 storey building. Probabilistic calculations of the structural response are carried out in frequency and time domains, and the parameters of the wind velocity field are calibrated on the basis of the time-histories of the global floor forces derived by experimental tests on a rigid 1:500 scale model of the building. The occupant comfort is related to the motion perception under moderate winds, and quantified by the probability of exceeding threshold values of the across-wind acceleration at the top of the building. The structural reliability is related to the lateral deformation capacity under strong winds, and quantified by the probability of exceeding threshold values of the maximum inter-storey drift ratio. The results of numerical analyses suggest the use of a tuned mass damper to enhance the building performances.