Abstract
The limitation of the commonly used nonlinear static procedures (NSPs), including the ones recommended by the seismic codes (Eurocode 8 – N2 method, ATC40 and FEMA440 – capacity spectrum method, CSM), is their inability to capture the torsional behaviour of plan-asymmetric buildings. Fajfar and his team have extended the N2 method to this kind of structures through the application of correction factors which depend on both linear dynamic response spectrum analysis and pushover analysis. In this chapter, the proposed correction factors are applied to the N2 method and to the CSM with the features recommended in FEMA440 in order to assess the seismic response of three existing plan irregular buildings. The torsional demands estimated by the aforementioned NSPs are duly compared with the ones defined by means of the most precise nonlinear dynamic analyses for several levels of seismic intensity. The torsional correction factors used seem to improve the performance of existing code pushover methodologies in estimating the seismic response of plan irregular structures.
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Acknowledgements
The authors would like to thank Dr Ihsan Bal for providing valuable data related to research work on the topic of this chapter. A special acknowledgement to Dr Rui Pinho for the valuable discussions that certainly enriched the work herein presented. The authors would like to acknowledge the financial support of the Portuguese Foundation for Science and Technology (Ministry of Science and Technology of the Republic of Portugal) through the research project PTDC/ECM/100299/2008 and through the PhD scholarship SFRH/BD/28447/2006 granted to Carlos Bhatt.
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Bhatt, C., Bento, R. (2013). Estimating Torsional Demands in Plan Irregular Buildings Using Pushover Procedures Coupled with Linear Dynamic Response Spectrum Analysis. In: Lavan, O., De Stefano, M. (eds) Seismic Behaviour and Design of Irregular and Complex Civil Structures. Geotechnical, Geological and Earthquake Engineering, vol 24. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-5377-8_15
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