Advanced Technical Issues Related to Wind Loading on Tall Building Structures in Consideration of Performance-Based Design

This paper addresses technical issues related to structural wind design of tall buildings and their effects on performance-based design (PBD). The issues include (i) across-wind loading due to vortex-shedding which is one of the governing design parameters for tall buildings, (ii) along-wind loading due to wind-buffeting and its probabilistic distribution for tall building design, and (iii) the comparison of wind design versus seismic design on PBD basis. The intended use of this study is to discuss about the cost-saving effect and feasibility of PBD compared to the conventional tall buildings' wind design by quantifying those effects based on an example of a typical tall building. The efficiency of wind design based on a PBD approach similar to that which has been applied to earthquake engineering is applied to the example of a tall building and the cost-saving effect of PBD is discussed based on the results. In order to derive generalized results, the study is performed for a generic tall building with a square plan of 30 m by 30 m, and a building height of 300 m, with a resulting aspect ratio (slenderness ratio) of ten (10). Dynamic structural properties of the building including building frequency, mass density and mode shapes are assumed based on the authors' experience with typical tall buildings. The across-wind and along-wind responses of the tall building are simulated for a range of return periods to discuss about the implication of performance-based wind design of tall buildings. The paper will provide insightful and practical information that structural engineers can use for their preliminary or detailed structural wind design of tall buildings.