ABSTRACT
When accessibility to repair damage to bridge columns is a problem, as in the case of multi-span continuous bridges over rivers, it is necessary to avoid the ultimate failure of the bridge columns as well as the seismic isolation bearings. In this study, improving the reparability of seismically isolated multi-span continuous girder bridges by the rupture of the anchor bolts of the deteriorated isolation bearings was investigated by incremental dynamic analysis and fragility analysis. As a result, it was shown that the ultimate failure of rubber layers of the seismic isolation bearings and the columns can be sufficiently avoided under extreme ground motions by the rupture of the anchor bolts, even if the ageing deterioration of bearings is considered.
