Investigation of aerodynamic and structural features of twisting tall buildings

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2019
Bilgen, Sinan
After decades of conventional shapes, irregular forms with complex geometries are getting more popular for form generation of tall buildings all over the world. This trend has recently brought out diverse building forms such as twisting tall buildings. This study investigates both the aerodynamic and structural features of twisting tall buildings through comparative analyses. Since twisting a tall building gives rise to additional complexities related with the form and structural system, lateral load effects become of greater importance on these buildings. The aim of this study is to analyze the inherent characteristics of these iconic forms by comparing the wind loads on twisting tall buildings with those on their prismatic twins. The prismatic twin of the twisting form was generated by removing the progressive rotation of the floors where the floor plan area and the story height kept the same. Through a case study research, aerodynamic analyses of an existing twisting tall building and its prismatic counterpart were performed, and the results have been compared. High-frequency base balance (HFBB) tests and synchronous pressure measurement tests on twisting and prismatic 3D models were performed to evaluate wind load effects. Comparisons of mean and maximum base moments with respect to different wind directions are performed together with the resultant moments. Performance-based analyses under investigation vi have been evaluated in accordance with the aerodynamic loads obtained from HFBB tests. This way, base shear forces, story displacements, torsional moments and the distribution of loads on structural members are examined. Comparisons highlight that, the twisting form under investigation is aerodynamically better due to less wind loads both for along and across wind directions. Compared to the prismatic counterpart; twisting model is competitor in terms of roof drift and member forces due to relatively less wind loads on it but subjected to higher torsion levels.

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Citation Formats
S. Bilgen, “Investigation of aerodynamic and structural features of twisting tall buildings,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Building Science in Architecture., Middle East Technical University, 2019.