ABSTRACT
Seismically isolated bridge shows non-linear response both at seismic isolators and columns where intensive earthquake hits the bridge. Such non-linear response characteristics are influenced by the hardening effect of the seismic isolator and over-strength effect of the bridge column. In order to clarify such non-linear behavior of the seismically isolated bridge, seismic response analyses are conducted considering hardening effect of the seismic isolator and uncertainties of non-linear parameters of the seismic isolator and the bridge column using Monte Calro techniques. According to this study, the hardening effect of seismic isolator increases the ductility response of the column and the strength demand of the isolators. Especially the hardening effect of seismic isolator increases the ductility response of the column; furthermore, this effect is more significant where much elongation of natural period by isolator is expected in design. Finally, based on the result of the analyses, the seismic reliability of isolated bridges are evaluated using safety index β.
