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

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.