ABSTRACT
The optimal intensity measures for the seismic fragility assessment of seismically isolated bridges were investigated by considering the hardening and variation in the mechanical properties due to the deterioration of lead rubber bearings. As a result, it was shown that SI for isolators and PGV for columns tend to have higher proficiency, which is a composite measure considering both practicality and efficiency. Furthermore, PGV was selected as the most practical intensity measure regardless of the difference in the seismic response characteristics of members and whether the lead rubber bearings are sound or deteriorated.
