Influence of vented floors on the across-wind response of tall buildings

Architectural form can be a significant factor influencing the performance of a tall building under across-wind excitation. When wind tunnel testing of a defined architectural form reveals undesirable behavior, it must be mitigated through engineering modifications such as the addition of structural material or supplementary damping devices. Alternatively, informed design of architectural forms enables a tall building's shape to be modified in a way that has the potential to significantly reduce its across-wind response. Introducing openings in the form of vented floors was explored to reduce across-wind excitation of a prismatic square building. Single and double-vented aerodynamic treatments were applied at various locations along the height of prismatic square benchmark buildings of 7:1, 8.5:1, and 10:1 slenderness. In total, 36 distinct architectural forms were tested at Skidmore, Owings & Merrill's experimental boundary layer wind tunnel facility to determine the effectiveness of the vents. A ‘zone of maximum influence’ was identified at approximately 60%–80% of the height of prismatic square buildings. ‘Optimal’ locations for single- and double-vents were determined within this influence zone. Full-scale peak moment and acceleration responses were estimated and compared to evaluate the dependence of venting treatment effectiveness on incident wind speed and flow turbulence.