ABSTRACT
The design of tall buildings subject to wind actions should be developed in the framework of Performance-Based Wind Engineering (PBWE), where risk assessment is coupled with a deci-sion strategy aimed at design optimization. PBWE is oriented at checking and ensuring, in prob-abilistic terms, the fulfillment of the structural performances (related to no collapse, life safety, accessibility, and full functionality). The performances are described by a set of measurable attributes, the decision variables, which are functionally related to (a) proper measures of the structural damage, in turn dependent on proper engineering demand parameters characterizing the structural response, and (b) measures of the intensity of the wind field. In this paper, PBWE is applied to the assessment of the comfort requirement of a 74 storey building. Probabilistic calculations of the structural response are carried out in frequency domain, but the parameters of the wind velocity field are calibrated on the basis of the time-histories of the floor forces derived by experimental tests on a rigid 1/500 scale model of the building. The occupant comfort is re-lated to the motion perception, and quantified by the probability of exceeding threshold values of the across-wind acceleration at the top of the building. The results of numerical analyses sug-gest the use of a Tuned Mass Damper to increase the level of occupant comfort.
Keywords: Wind Engineering, Performance-Based Design, Risk Assessment, Tall Buildings, Dynamic Response, Occupant Comfort.
