ABSTRACT
ABSTRACT: An elastic analysis procedure for the design of seismic-isolated bridges (SIB) is presented in AASHTO (American Association of State Highway Transportation Officials) Guide Specifications for Seismic Isolation Design (AASHTO 1999). Since the behavior of seismic isolators is non-linear in nature, equivalent linear (EL) properties need to be defined for the elastic analysis of SIB. The EL properties of SIB are expressed in terms of an effective stiffness, an effective period and an effective damping (ED) ratio to account for the hysteretic energy dissipation of the isolators. Using these EL properties, an EL analysis procedure is followed to estimate the absolute maximum seismic responses in the isolators and in other components of the bridge.
