EFFECT OF BASE ISOLATION IN MULTISTORIED RC IRREGULAR BUILDING USING TIME HISTORY ANALYSIS

Vinodkumar Parma, G.S.Hiremath

Abstract: Base isolation (BI) is a technique that has been used around the world to protect the building structures from the damaging effects of earthquake. The installation of isolator in building at base level significantly increases the time period of the structure, which means it reduces the possibility of resonance of the structure giving rise to better seismic performance of the building. The study is performed to compare the effectiveness of base isolation in plan irregular and vertical irregular multi-storied RC frame building. For this study, 15 storied R.C frame building is considered and Time History analysis is carried out using ETABS 2013 software. The Lead Rubber Bearing (LRB) is designed as per UBC 97 code and the same was used for analysis of base isolation system. The results obtained from the analysis were time period and base shear. Time period for the base isolated structures are higher than that of the fixed base structure. Due to the presence of isolator, Base shear is significantly reduced in each direction (X and Y direction) as compared to fixed base building. It has been found that when compared to plan irregular base isolated building the vertical irregular building gives better performance in high seismic prone area by using isolators at the base of the building

Keywords: Base isolation, Lead rubber bearing, Time history analysis, Irregular building

DOI: https://doi.org/10.15623/ijret.2015.0406048