Author : Krishnagadha S.J 1
Date of Publication :7th September 2016
Abstract: Earthquakes are one amongst nature’s greatest hazards; throughout historic time they have caused significant loss of life and severe damage to property, especially to man-made structures. A large proportion of world’s population lives in regions of seismic hazards. The application of the base isolation techniques to protect structures against damage from earthquake attacks has been considered as one of the most effective approaches and has gained increasing acceptance during the last two decades. Seismic isolation system consists of the installation mechanisms which isolates the structure from the base by providing seismic isolators. The seismic isolation system is mounted beneath the superstructure and is referred as ‘Base Isolation’. The main purpose of the base isolation device is to minimize the horizontal acceleration transmitted to the superstructure. Base isolation is very promising technology to protect different structures like building, bridges, airport terminals and nuclear power plants etc. from seismic excitation. This work pertains to the study of a G+8 storeyed hospital building. To compare the seismic effects of fixed base structure with respect to isolated structure, the building was analysed using response spectrum and Time history(El-Centro, having magnitude 6.9)methods. When the fixed frame structure was analyzed, the top storey displacement, base shear, inter storey drifts and end moments were found to be beyond the limits of IS1983-2002. Inorder to reduce them, LRB(Lead Rubber Bearing) base isolators were installed at the base of the building. The report also includes the comparative study of the building with and without isolators.
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