Sliding Isolation System for Bridges: Analytical Study

Abstract

This paper reports on a parametric study of the response of bridges supported by an isolation system consisting of sliding Teflon bearings and displacement control devices. The isolated bridges are subjected to simulated earthquake motions which are compatible with CalTrans design spectra. The effects of isolation system properties, deck flexibility, pier flexibility, pier strength, distribution of isolation elements and earthquake type are investigated. Results are presented in a form that is useful in the design of sliding isolation systems for two-span continuous deck bridges. Comparisons with the response of conventionally built bridges demonstrate the significant benefits of seismic isolation. Finally, simplified code-type analysis procedures are presented and evaluated.