Seismic fragility assessment of a multi-span continuous I-girder bridge controlled by a self-centering damper

초록

This study evaluated the seismic fragility and failure modes of a reinforced concrete bridge retrofitted with a selfcentering damper. This damper was hybrid and included two parts. The first part was a butterfly-shaped metallic damper, which provided the dissipating energy, and the second part was prestressed polyurethanes, which played a self-centering role in the damper. In particular, an extensive time history analysis was performed on three scenarios. These scenarios include the behavior of 1) the bridge with restrainer (Bridge-R), 2) the bridge with the damper (Bridge-D), and 3) the bridge with restrainer and damper in the longitudinal and transverse directions, respectively (Bridge-RD). Notably, the seismic fragility curves of bridge components were generated first, and eventually, the bridge seismic fragility curve was generated before and after the bridge was retrofitted with the hybrid damper. The analysis showed that the damper could have a positive effect on the residual displacements of the deck and bearing and the shear key deformation in the bridges. However, the damper increased the rigidity between the deck and columns and led to extra demand in the columns, but the extra demand had no effect on the general behavior of the bridges.

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