Seismic Performance of Isolated Bridges Considering Long-term Deterioration of Isolators

Abstract

Mechanical properties of natural rubber seismic isolators are varied due to aging deterioration. It is needed that seismic performance of isolated bridges are maintained considering aging deterioration of isolators over their lifetime. In this study, seismic failure modes and seismic safety of isolated bridges were evaluated considering uncertainties in the material and mechanical properties and aging deterioration of isolators. It was shown that seismic safety of the isolated bridges is mainly controlled by the rupture strain of the isolator if the ultimate capacity ratio between the isolator and the column is low and that adequate capacity ratio is needed to enhance seismic safety and reparability of isolated bridges.