CONTROL OF SEISMIC RESPONSE OF STRUCTURE USING FRICTION PENDULUM ISOLATOR WITH VISCOUS DAMPER

Abstract

Some natural or man-made effects may be cause of minor or major create vibration on earth’s surface. So a building resting on it will experience motion, which depends on magnitude of earthquake. This unpredictable earthquake motion has kinetic energy, which is also responsible for the generation of inertia force and if transmitted to structure, may cause damage of structure. So the knowledge about the earthquake, its behavior and their effects on structures grew with time and seismic resistant design procedures have been started. Base isolation is the most widely used in seismic resistant systems used in building in earthquake prone areas. The object of this study is to reduce the base shear, story displacement and story drifts due to earthquake ground excitation, applied to the superstructure of the building by installing base isolation devices at the foundation level and then to compare the different performances between the fixed base condition and baseisolated condition (FPS) by using SAP2000v15 software. In this study, the 7-story symmetrical R.C.C. building is used as test model. Non-linear time history analysis is used on both fixed base and base isolated multistory buildings. There are two studies; one is comparative study of response of fixed base condition and base isolation (FPS) condition and the comparative study of performance by two different time histories LACC and Newhall T.H. Finally, base shear, displacement and acceleration are compared from two times histories analysis between fixed base conditions. It is found that the displacement is increased with time period of the isolated building. FPS design parameters depend on the coefficient of friction. So in this study behavior of friction pendulum system is found out with variation of value of coefficient of friction, which depends on property of lubricating material. By use of isolator system we can decrease the acceleration, but the displacement at different stories is increase, and might collide with sidewalls or stoppers due to excessively severe ground motions. To control these response displacements of the base isolated structures by means of viscous damper with coupling mechanism. In this study, results of the software SAP2000v15, 7-story base isolated structure specimen is shown to investigate the performance the effectiveness of the proposed device.