High-Rise Reinforced Concrete Structures: Database-Assisted Design for Wind

Abstract

Advances in wind pressure measurement and computer technology have made time-domain analyses of wind effects on high-rise structures possible in recent years. Time-domain solutions use aerodynamic and wind climatological databases and provide full phase information on wind-induced response that is lost in the frequency-domain approach; therefore, they can account rigorously for the superposed effects of any number of modes of vibration of any shape; for mode coupling; for wind directionality effects; and for the joint contributions of axial forces, bending moments, and shear forces in interaction equations used for structural design. Unlike the frequency-domain approach, in the time-domain approach, the process of determining wind effects and the structural design process, referred to jointly as database-assisted design (DAD), are integrated, transparent, and fully auditable. The objective of this study is to present the DAD approach as applied to high-rise reinforced concrete (RC) buildings. Given the time histories of pressures, measured in the wind tunnel at a sufficient number of taps on the exterior faces of the building envelope for a sufficient number of mean speed directions and a preliminary design of the building, the structural engineer can calculate, as functions of wind speed and direction: (1) demand-to-capacity indexes for any number of members and cross sections, (2) interstory drift, (3) and top floor accelerations. These responses are properties of the structure independent of the wind climate, and constitute response databases used in conjunction with a wind climatological database to obtain the requisite wind effects for any specified mean recurrence interval. The design, which accounts for both wind and gravity effects, is performed iteratively until the design specifications are satisfied.