Seismic fragility and resilience improvement of conventional bridges supported by double-column piers utilizing shear links

A bridge structure is one of the most vulnerable parts of the transportation network system subjected to earthquakes. It is paramount to the seismic capacity improvement and the rapid recovery function of bridges during earthquakes. To address these challenges, shear links (SLs) are designed between the columns supporting the continuous girder bridges based on the structural fuse concept. The impacts of SLs on the life-cycle performance and seismic resilience of continuous girder bridges were studied by comparing the continuous girder bridges supported by double-column piers with and without SLs. The incremental dynamic analyses were per-formed to evaluate the seismic fragility of continuous girder bridges supported by double-column piers with and without SLs under the far-and near-field seismic waves. The economic losses were assessed to compare the financial superiority of continuous girder bridges supported by double-column piers with SLs in the life cycle. A resilience assessment methodology was employed to evaluate the post-earthquake resilience of continuous girder bridges supported by double-column piers with and without SLs. The results showed that the SLs preferentially dissipated a certain amount of earthquake energy so that the continuous girder bridge supported by new-type double-column piers with SLs exhibited lower seismic fragility and life-cycle losses compared to the continuous girder bridge supported by traditional double-column piers. Also, the proposed continuous girder bridge supported by new-type double-column piers with SLs behaved with higher post-earthquake resilience under the far-and near-field seismic waves.