00-0012 Experimental Evaluation of Seismic Performance of Bridge Restrainers A.G. Vlassis, E.M. Maragakis and M. Saiid Saiidi 2000 University of Nevada, Reno 160 PB2001-104354 30 The overall objective of this task was to conduct shake table tests to evaluate the seismic performance of bridges that have been retrofitted with hinge restrainers between simply supported adjacent spans. This experimental study investigates the impact between adjacent bridge spans at in-span hinges, evaluates the efficacy of restrainers in reducing relative displacement across the hinges and examines the effects of restrainer stiffness and gap on the response of the hinge-restrainer system. Experimental results indicated that impacts between the adjacent frameworks produce acceleration levels significantly higher than what is typically assumed in design. Restrainers were capable of reducing hinge relative displacements and preventing span unseating. However, restrainer yielding occurred under strong input motions, especially when the restrainer gap was set to zero. Only pounding at the hinge locations was included in this study, while pounding elsewhere in the superstructure as well as the detailed response behavior of substructure elements were neglected. Shaking table tests. Highway bridges. Retrofitting. Hinge restrainers. Pounding. Earthquake. Engineering. Adjacent spans.