The Structural Design of Tall and Special Buildings

Koosha, Ali; Pahlavan, Hossein; Amiri, Mohammad Shamekhi

doi: 10.1002/tal.70053pmid: N/A

High‐rise buildings are particularly susceptible to structural damage during long‐period ground motions because of resonance effects. This study employs seismic fragility analysis through incremental dynamic analysis (IDA) to evaluate the extent of damage in such structures under long‐period excitations. A notable contribution of this research is the incorporation of probabilistic vulnerability assessment across multiple damage states, offering a comprehensive insight into the seismic performance of reinforced concrete (RC) frame‐core buildings with hybrid coupled shear walls. Three structural models, 15‐, 25‐, and 35‐story buildings with identical architectural configurations, were analyzed using Perform‐3D software. The findings reveal a marked increase in seismic vulnerability under long‐period ground motions. As structural damage progresses from slight to moderate, extensive, and ultimately complete, the difference in fragility between long‐ and short‐period excitations becomes increasingly evident. Notably, at the complete damage state, the median seismic fragility capacity under long‐period excitations decreases by approximately 60%, underscoring the significant adverse effect of such excitations on the seismic performance of high‐rise buildings.

doi: 10.1002/tal.2144pmid: N/A

No abstract is available for this article.

Mandal, Shanku; Dalui, Sujit Kumar; Bhattacharjya, Soumya

doi: 10.1002/tal.70052pmid: N/A

In the field of architecture, U plan–shaped buildings are quite popular for extracting maximum air and light from the atmosphere. However, the design of such structures under random wind effects is not straightforward due to the unavailability of moment, shear, and force coefficients in the design standards. Thus, in this research, an attempt is made to develop a chart that can be readily used for wind design of U plan–shaped buildings of an extended range of side ratio (SR) and aspect ratio (AR) in different terrains (TR). For doing this, the wind effect is simulated through computational fluid dynamics (CFD) in Ansys. Subsequently, the nonstationary stochastic nature of wind force is also considered through a linear time‐history analysis accounting for flexibility and frame stiffness of the structure. The modification factors are obtained as the ratio of force coefficient, base shear, and moment of the U plan–shaped building to that of an equivalent square plan–shaped building. This form of modification factor also reflects the beneficial or detrimental effect of the U‐plan shape compared to the conventional rectangular plan–shaped buildings. The obtained set of modification factors is validated with already published data and observed to be in close conformity with the experimental results. This study further illustrates that the structural reactions of the building models are markedly influenced by the buildings' SR, AR, and the surrounding topography, as evidenced by the comparison of peak displacement responses.