Wind Loading on Tall Building Structures in Consideration of Performance-Based Design

Tall buildings are vulnerable to wind loads owing to their structural and aerodynamic characteristics, and their designs are frequently governed by wind loads over other design loads such as seismic loads, even in active seismic regions. Performance-based wind design (PBWD) has been suggested to overcome the drawbacks (usually conservative design) of current building wind design practice based on allowable stress design (ASD) and/or load resistant factored design (LRFD) by explicitly satisfying performance levels set out for different level of probabilities and intensities. Because of the unique nature of wind loads on tall buildings, it is intuitive that once a building is designed in elastic range for the short return period, it will remain elastic even for much higher return periods. Using a typical tall building example, the main components of PBWD are discussed and compared to those of PBSD to examine the feasibility of expected material-saving effects of PBWD. Findings conclude that the “heavy-headed, light-tailed” probabilistic distribution of wind speeds and building aerodynamic characteristics weaken the application of performance-based design to tall building wind design.