Date of this Version
Garcia, F. 2018. A Review of the Seismic Isolation Design Procedure. Undergraduate Honors Thesis. University of Nebraska-Lincoln.
The current design procedure for seismic isolation bearings for bridges is a simplified method that assigns the bearings with an elastic stiffness. Bridges subjected to ground motions actually act in a hysteric, nonlinear fashion when force is plotted against displacement. The goal of this research was to gain further insight as to whether simplifying seismic isolation bearings to a simplified stiffness is adequate or not. Design procedures were followed in the modeling of a bridge with seismic isolation. Linear modal time history analyses and with nonlinear direct integration time history analyses of ground motions were compared. At the conclusion of this study, it is still unclear as to whether the simplification of the bearings’ motions that are used in contemporary bridge design were adequate or not. It should be noted that structural modeling methods are very sensitive that require rigorous and complex calculations to check. Additional work would be required on the bridge model developed in order to determine whether the current design standards for seismic isolators are adequate.