Seismic base isolation in reinforce concretestructure

Base isolation is one of the most widely accepted seismic protection systems used in building in earthquake prone areas. The base isolation system separates the structure from its foundation and primarily moves it relative to that of the upper structure. The aim of this study is to reduce the base shear 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 base-isolated condition .The static equivalent lateral force of analysis, response spectrum and time history analysis and used on both of fixed base and base isolated buildings The key references that are used in this study are the related chapters of IBC2006 code for seismic isolated structures. In this work, this code is used for the design examples of elastomeric bearings. Furthermore, the internal forces develop in the superstructure during a ground motion is determined; and the different approaches defined by the codes towards the 'scaling factor' concept is compared in this perspective.