Aerodynamic Responses of Tall Buildings with Cross-Section Modification Through Additive- and Subtractive-Based Strategies

Aerodynamic modifications are recognized as an effective approach to mitigate wind responses for tall buildings. However, the relative effectiveness is highly dependent on (1) the benchmark (reference) model, and (2) the design wind speeds. In this study, a total of 21 cross-section modification models and 4 square benchmark models were tested using high-frequency force balance wind tunnel testing. The aerodynamic performance of the 21 models is assessed from both the perspective of additive-based side protrusions and subtractive-based corner recessions under a broad range of design wind speeds. The results indicate that the subtractive-based corner recession strategy has a higher chance to produce adverse responses at low wind speeds. On the contrary, promising aerodynamic performance under a broad range of wind speeds can be achieved via the additive-based side protrusion strategy using various protrusion ratios (PRs). Models SP-7-86, SP-14-71, and SP-21-29 are the ideal candidates for minor, medium, and major side protrusion strategies, respectively. The overturning moment (OTM) responses at the wind speeds of 53 m/s for the three models are reduced by 35%, 50%, and 48%, respectively.