COMPARATIVE STUDY OF RC FRAMED STRUCTURES USING SPECTRA BASED PUSHOVER ANALYSIS

Abstract

Spectra based multimodal adaptive pushover analysis considers higher modes of vibration and combines them using SRSS rule and scale factors. Damage index for the structures are calculated to evaluate the degree of damage occurred after a seismic event. For the present study the Spectra based multimodal adaptive pushover analysis is adopted for G+ 4 storeys Symmetric and G+ 4 storeys Asymmetric Reinforced concrete framed structures. The Expended Energy based damage index methods are used to calculate Damage Index for symmetric and asymmetric structures. ETABS 2015 software is utilized for modeling and analysis of Reinforced concrete framed structures. The comparative studies are carried out between the structure considering only 1st mode and considering all modes and compared between 3 methods of damage index. It is observed that the capacity obtained by considering all modes is less than the capacity obtained by considering only 1st mode. The target displacement obtained considering only 1st mode is less than the target displacement obtained considering all modes. And the damage index obtained by considering all modes is more than the damage index obtained by considering only 1st mode. Therefore it is necessary to consider all modes to get accurate results. In asymmetric building the ductility is less, the capacity is less, demand is high, and degree of damage is more when compared with symmetric building.