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

Characteristics of aerodynamic forces and pressures on square plan buildings with height variations

Usually the design of the external shape and orientation of buildings is driven by architectural considerations, functional requirements and site limitations, rather than by aerodynamic considerations. This, most of the times, results in structures becoming bluff bodies characterized by high wind-structure interaction induced loads. These effects can be significantly reduced through novel aerodynamic mitigation techniques and optimal aerodynamic shape design procedures. This paper reviews the past/recent work on various aerodynamic mitigation techniques developed for reducing wind loads on buildings by modifying their shapes and/or adding simple architectural elements. Aerodynamic mitigation techniques applicable to low-rise and high-rise buildings have been reviewed. In addition, aerodynamic shape optimization techniques for reducing wind loads on tall buildings are presented and the suitability and challenges of using Computational Fluids Dynamics (CFD) for this application are discussed. An overview of the optimization techniques namely gradient based methods and non-gradient based methods are presented. It is expected that this research can ignite an interest in using aerodynamic shapes and consideration of the structures’ shape, in terms of wind performance, early in the design process. This paper also serves as a source for various techniques that can be used for reducing wind loads on buildings.

Aerodynamic Mitigation and Shape Optimization of Buildings: Review

Across-wind responses of an aeroelastic tapered tall building

With the advancement in construction and engineering techniques, a pragmatic shift in architectural designs of tall buildings can be observed. The buildings are going taller and unconventional shaped rather than traditional. Generally shape and orientation of the building are determined on the basis of architectural and practical considerations, but the wind-induced excitations encouraged by bluffness of the building shapes cannot be neglected also. To safeguard the functional requirement of tall flexible buildings and to mitigate the excitations, various methods are available. Among these methods, aerodynamic modification techniques are very potent, which affect the mechanism of vortex shedding phenomenon considerably and have got a lot of attention in recent years. Based on the impact of modification on the outer architecture of the building, the aerodynamic modifications are categorized in two groups i.e. minor modifications (corner cut, rounding, chamfer etc.) and major modifications (taper, set-back, twist etc.). The present study comprehensively reviews the recent/past aerodynamic modification techniques applied to high-rise buildings.

Ki-Pou You

Papers

Dynamic responses of a tapered tall building to wind loads