Vibrationand oscillation of a high-rise structure should be limited to avoid discomfortto users and damage contents. For special structures, including long-spanbridges, large stadium roofs and chimneys, and wind-sensitive tall buildings,wind tunnel model tests are recommended for their wind-resistant design to meetvarious serviceability limits. The serviceability limit states on oscillation, deflection,and acceleration should be checked to ensure serviceable condition for thestructure during its service life. The checking procedure for motion perceptioncan be performed by comparing the magnitude of wind-induced vibration and acceptabilitythreshold of motion (or so-called occupant comfort criteria). It has beenwidely accepted that the perception of wind-induced motion is closely related tothe acceleration response of buildings (Kwok et al.
2007). Both peakacceleration and standard deviation acceleration under extreme wind conditionsof 10-year or 5-year return period are commonly used to represent buildingmotion (Burton et al. 2007).Severalresearchers have suggested introducing acceleration limit states in preventing occupantdiscomfort as a new design performance level for wind-sensitive buildings(Griffis 1993; Isyumov 1994). Acceleration and occupant comfort criteria forbuildings undergoing complex motions were discussed by Melbourne and Palmer(1992). In that study, acceleration criteria to achieve acceptable occupancy comfortin buildings have been developed in terms of peak accelerations as a functionof motion frequency and return period. In terms of performance-based windengineering, Chock et al. (1998) proposed a compatible set of wind design criteriawhich would be “risk-consistent” with the current framework for performance-basedseismic engineering.
Performance-based wind engineering design levelsrecommended by Chock et al. are given in Table 1.1. In the table, the designlife of a building, which represents the exposure time for the building, is typicallytaken as 50 years to evaluate the probability of exceedance from the particularwind design level.
Interms of wind climatology, it is necessary to performing a site-specific designwind speed investigation, in which wind directionality and topographicaleffects would be considered. Jain et al. (2001) proposed a probability-basedmethodology used to determine site-specific performance-based design windspeeds for use in wind tunnel measurements and building design.