SEISMIC ANALYSIS OF VERTICAL IRREGULAR MULTISTORIED BUILDING

Abstract

It is understood that buildings which are regular in elevation (regular building) perform much better than those which have irregularity in elevation (irregular building) under seismic loading. Irregularities are not avoidable in construction of buildings. However a detailed study to understand structural behaviour of the buildings with irregularities under seismic loading is essential for appropriate design and their better performance. The main objective of this study is to understand the effect of elevation irregularity and behaviour of 3-D R.C. Building which is subjected to earthquake load. In the present study, a 5 bays X 5 bays, 16 storied structure with provision of lift core walls and each storey height 3.2 m, having irregularity in elevation, is considered as the soft storey 3-D structure. An Irregular building is assumed to be located in all zones. Linear dynamic analysis using Response Spectrum method of the irregular building is carried out using the standard and convenient FE software package. To quantify the effect of different degrees of irregularities all the structures are analysed. In addition, the analysis carried out also enables to understand the behaviour that takes place in irregular buildings in comparison to that in regular buildings. For this the behaviour parameters considered are 1) Maximum displacement 2) Base shear, 3) Time period.