A New Procedure to Include Torsional Effects in Pushover Analysis of Torsional Buildings

Authors

  • Rahul Leslie
  • Abhilash R.
  • Saraswathy B.

Keywords:

Pushover analysis, Torsional Buildings, Eccentric Buildings, SAP2000

Abstract

Non-linear Static analysis or Pushover analysis is a very practical method fit for day to day use in the structural design field, when compared to Non-linear Time History analysis due to its computational intensity and experienced judgement required. However it is found that Non-linear Time History analysis is more accurate than Pushover analysis, the disadvantage being more pronounced in case of irregular and torsional buildings. With conventional PoA, the torsional effects are mostly pronounced in the elastic range and early stages of plastic behaviour and tend to decrease with an increase in the plastic deformations, thus failing to capture the effects of torsion in buildings. The obvious answer being the inclusion of torsional elements in the lateral load pattern, a new method by which the eigen vectors are translated to its corresponding lateral load vectors with the torsional aspect included is proposed. On investigation it is found to overcome the above drawback and gives results closer to that of Non-linear Time History analysis, especially for irregular torsional buildings.

 

References

ATC-40, “Seismic Evaluation and Retrofit of Concrete Buildingsâ€, Vol. 1, Applied Technology Council, Redwood City, CA, U.S.A., 1996

FEMA-356, “Prestandard and Commentary for the Seismic Rehabilitation of Buildingsâ€, Federal Emergency Management Agency, Washington, DC, U.S.A., 2000

Kilar V, Fajfar P, “On The Applicability of Pushover Analysis to the Seismic Performance Evaluation of Asymmetric Buildingsâ€, European Earthquake Engineering, 15(1), pp. 20-31, 2001

Penelis G, Kappos A J, “3-D pushover analysis: The issue of torsionâ€, Proceedings of the 12th European Conference on Earthquake Engineering (Paper 015), Elsevier Science Ltd., 2002

CSI Inc., “Analysis Reference Manual for SAP2000, ETABS, and SAFEâ€, Computers and Structures, Inc., California, USA., 2008

IS:1893-2002, “Indian Standard Criteria for Earthquake Resistant Design of Structures, Part 1: General Provisions and Buildingsâ€, Bureau of Indian Standards, New Delhi, India., 2002

Fajfar P, MaruÅ¡ic D, Perus I, “The Extension of the N2 Method to Asymmetric Buildingsâ€, Proceedings of the 4th European workshop on the seismic behaviour of irregular and complex structures, Thessaloniki, 2005

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How to Cite

Leslie, R., R., A., & B., S. (2015). A New Procedure to Include Torsional Effects in Pushover Analysis of Torsional Buildings. Asian Journal of Engineering and Technology, 3(4). Retrieved from https://www.ajouronline.com/index.php/AJET/article/view/3146

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