Usage of seismic isolators against earthquake in building structures

The aim of this Master of Science thesis is to study seismic isolators, their mechanical characteristics and their usage in computer software as well as comparison of an existing fixed-base structure with the same structure which is base isolated. In the second chapter of this study which consists of eight chapters including the introduction and the conclusion chapters, seismic isolators used against earthquake are classified and information about their characteristics are given. In the third chapter, mechanical characteristics of rubber bearings, lead-plug bearings and friction pendulum systems and information necessary to define the behaviour of these bearings are given respectively. The UBC regulations are examined and in the fourth chapter, the base isolation terms of this regulations are given. To analyse an existing structure with different isolation bearing systems in a computerized media, SAP2000, one of a few software available that can make this analysis has been chosen and the acceptances and its properties are given in chapter five. In chapter six, calculations of an existing reinforced concrete structure on which high damping rubber bearing, lead-plug bearing and friction pendulum bearing applied are given step by step. Results achieved from static and nonlinear time history analysis that compared with the fixed base structure case denoted that base isolation application in structural systems is a valid method in building design against earthquake. In chapter seven, with the terms given by UBC regulations, for 3 different bearing types used in this study programmed in Visual Basic programming language, source codes that deemed important are presented in Appendix 3. Keywords: Base isolation, vibration, earthquake, rubber bearings, friction pendulum systems, UBC, SAP2000.