A major cause of bridge failure during earthquakes is the collapse of bridge decks due to unseating at the intermediate supports and abutments. An effective method to reduce the probability of unseating is to use restrainer cables at the hinges and abutments in simply supported bridges. A full-scale bridge setup is constructed based on an existing steel girder bridge in Tennessee, which has been considered for seismic retrofit using restrainer cables. Seismic restrainer cables are connected to the bridge pier using steel bent plates, angles, and undercut anchors embedded in the concrete, as specified by typical bridge plans. The full-scale bridge model was subjected to monotonic loading to test the capacity of the restrainer cable system and determine the modes of failure. Test results show that non-ductile failures occur in the steel bent plate connections in the restrainer systems at loads less than 10% of the restrainer cable capacity. A modified connection using steel angles is used to replace the bent plate connections. The steel angle connection resulted in much higher capacity compared to the bent plates. However, the connection still did not exceed the yield capacity of the restrainers, and resulted in large deformations before failure. Finally, a restrainer cable, using a stiffened angle connection is tested. The modified connection demonstrated much better performance, both in terms of stiffness and deformation.
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