Seismic performance assessment of bridges with deteriorated isolators

Mechanical properties of natural rubber seismic isolators are varied due to aging deterioration. In this study, the effects of long-term aging deterioration of seismic isolators on the seismic behavior, safety and reparablity of isolated bridges were investigated based on incremental dynamic analysis using various observed ground motions. As a result, it was shown that seismic safety and reparability of isolated bridges can be enhanced by setting adequate ultimate capacity ratio between the isolator and the column and enhancing the performance of the bridge column which is finally induced seismic damage under severe ground motions.