Experimental investigation of aerodynamic forces and wind pressures acting on tall buildings with various unconventional configurations

Tall buildings have been traditionally designed to be symmetric rectangular, triangular or circular in plan, in order to avoid excessive seismic-induced torsional vibrations due to eccentricity, especially in seismic-prone regions like Japan. However, recent tall building design has been released from the spell of compulsory symmetric shape design, and free-style design is increasing. This is mainly due to architects’ and structural designers’ challenging demands for novel and unconventional expressions. Another important aspect is that rather complicated sectional shapes are basically good with regard to aerodynamic properties for crosswind excitations, which are a key issue in tall-building wind-resistant design. A series of wind tunnel experiments have been carried out to determine aerodynamic forces and wind pressures acting on square-plan tall building models with various configurations: corner cut, setbacks, helical and so on. The results of these experiments have led to comprehensive understanding of the aerodynamic characteristics of tall buildings with various configurations.