Analytical Assessment of Pros and Cons for Prevalent Tall Building System in Comparison with Tube System Using ASCE7-05 Wind Load Specifications

Tall buildings classify as interior and exterior systems regarding to structural system. Important forms of exterior systems are tube, tube-in-tube w/o interior core, tube-in-tube with outrigger, braced tube and bundled tube. In order to evaluate pros and cons of each system, full 3D model implemented by using SAP2000 and seismic performance assessment defined as a major aim of this research. Shear absorption, story drift, inter story drift, shear lag factor (SLF), fundamental period and maximum along-wind displacement and acceleration are evaluated parameters.
The qualitative results showed that using aforementioned led to improve seismic response of building compared with tube system. However, a considerable effect on response reduction observed by using braced system. On the other hand, variation rate of SLF on columns located at tension flange was much uniform. In addition, SLF became one on the upper floors in all cases. Finally, by using braced tube, and maximum along-wind displacement and acceleration calculated with ASCE705 meet the comfort criterion of occupants.