Seismic Vulnerability Assessment of a Multi-Span Continuous Highway Bridge Fitted with Shape Memory Alloy Bars and Laminated Rubber Bearings

This study performs seismic vulnerability assessment in the longitudinal direction of a three-span continuous highway bridge, restrained by shape memory alloy (SMA) bars and isolated with laminated rubber bearings. The analytical simulation method based on incremental dynamic analyses is used in evaluating the seismic fragility functions of the bridge components (pier and isolation bearing) and the system. A two-dimensional finite element model scheme with nonlinear force-displacement relationships is used for the bridge piers and bearings. This study shows that the bridge piers with SMA bars have led to relatively higher seismic vulnerability over the bridge piers without SMA bars, which is also reflected in the bridge system. The isolation bearings with SMA bars have revealed comparatively less seismic vulnerability than those without SMA bars. From the numerical results, it is recognized that the failure probability of the bridge system is dictated by the bridge pier over the isolation bearing.