A Simplified Parametric Study on Occupant Comfort Conditions in Base Isolated Buildings under Wind Loading

Vibrations in buildings can cause occupant discomfort in the form of annoyance, headache, or sickness. While occupant comfort is considered in international standards regarding the design of high rise buildings against wind loading, it is neglected in the design of buildings with seismic protective base isolation systems. Nevertheless, due to their low flexibility, base isolated buildings can be prone to wind-induced vibrations, which makes occupant discomfort a potentially significant serviceability limit state. This paper presents a study on occupant comfort conditions in wind-excited base isolated buildings. A numerical simplified parametric procedure is proposed in order to evaluate the return period of wind events causing human discomfort. A parametric investigation is then presented to evaluate the effects of salient parameters on comfort conditions. The procedure is based on (i) the nonlinear dynamic analysis of the structure modeled as a single-degree-of-freedom oscillator with hysteretic base isolators, (ii) the digital generation of time histories of turbulent wind velocity, and (iii) comfort evaluations based on international standards. Results demonstrate that discomfort conditions can occur a few times in a year, depending upon the wind-exposure of the site, what suggests considering this serviceability limit state in the design of base isolated buildings.