Nonlinear dynamic analysis of viscoelastic base isolated building structures

SUMMARY Nonlinear Dynamic Analysis of Viscoelastic Base Isolated Building Structures In this study, nonlinear dynamic analysis of viscoelastic base isolated buildings is performed by using frictional pendulum system and lead rubber isolation bearing. Protecting buildings from damages caused by strong earthquakes have been always in the agenda of the researchers and engineers in the field of earthquake engineering. As a result, the usage of isolation techniques, which isolate the building from the ground, to reduce the effects of the earthquake on the building has become the focus of attention These isolation devices are called seismic isolators or base isolators in the engineering. The techniques used in the buildings provide many advantages. Firstly, the process of isolation causes to reduce the fundamental frequency of the superstructure and makes the superstructure less stiffer. The deformation also occurs at the isolators. Therefore, the superstructure remains almost rigid and the resistance of the structure against earthquake ground motion incredibly increases. The second advantage is that transmitted acceleration to the superstructure due to earthquake motion is reduced and the isolation techniques pro vide flexibility without reducing the safety of the building. This will lead to a known fact that the structure will likely to experience less dynamic forces. 18 May El-Centro and 13 March 1992 Erzincan earthquakes are used as earthquake records in time history analysis. The results obtained are compared. This thesis consists of seven chapters. In the first chapter, the historical development of base isolated structures, the previous works, the formulation and the equation of motion of base isolated structures, the solution algorithm are presented. In the second chapter, the nonlinear dynamic analysis of building structures either base isolated or fixed base, are performed. In addition, the effect of shear walls for these buildings is considered. In the third chapter, the results ob tained from the nonlinear dynamic analysis of base isolated buildings using various earth quake records are presented. In the fourth chapter, the results obtained from these analyses are examined. In the fifth chapter, the conclusions and suggestions drawn are explained. In the sixth chapter implies references used in this study. In the seventh chapter, the curricu lum vitae of the author of this thesis is presented. Key Words : Base Isolated Building, Nonlinear Analysis, Time History Analysis, Force- Deformation Curve, Lead Rubber and Frictional Pendulum System X