Analysis and performance assessment of a seismic isolated RC bridge

The main goal of adding seismic isolation systems to stuctures used for road transportation such as bridges and viaducts is to increase the natural period of the structure by seperating infrastructure and superstructure by means of link elements having relatively low lateral stiffness. Therefore, accelerations transferred to the superstructure, accordingly inertia forces, are decreased.In this study; non-linear behavior of seismic isolation system added to a multi-span reinforced concrete bridge with a box cross-section was analyzed and the effect of high damping rubber seismic isolation systems on the performance of the reinforced concrete structure was investigated. Demands and relative drift ratios of the bridge modelled using rigid joints and the bridge with seismic isolation system modelled using link elements were compared. Performance evaluations for both models were conducted by employing incremental pushover analyses, nonlinear static pushover analyses and nonlinear time-history analyses. The code by AASHTO (American Association of State Highway and Transportation Officials), which is used widely for adding seismic isolation systems to bridges, is used.