Seismic Performance Evaluation of a Fully Integral Concrete Bridge with End-Restraining Abutments

Abstract

A fully integral bridge that is restrained at both ends by the abutments has been proposed to form a monolithic rigid frame structure. Thus, the feasible horizontal force effect due to an earthquake or vehicle braking is mainly prevented by the endrestraining abutments. In a recent study, a fully integral bridge with appropriate end-restraining abutment stiffness was derived foramultispancontinuousrailroadbridgebasedonlinearelasticbehavior.Therefore,thisstudyaimstoinvestigatethenonlinear behavior and seismic capacity of the fully integral bridge and then to assess the appropriate stiffness of the end-restraining abutmenttosufficientlyresistdesignearthquakeloadingsthrougharigorousparametricstudy.Thefiniteelementmodelingand analyses are performed using OpenSees. In order to obtain the force-deflection curves of the models, nonlinear static pushover analysis isperformed.It isconfirmedthatthefullyintegralbridge prototypeinthestudy meetstheseismicperformancecriteria specifiedbyCaltrans.Thenonlinearstaticpushoveranalysisresultsrevealthat,duetotheend-restrainingeffectoftheabutment, the lateral displacement of the fully integral bridge is reduced, and the intermediate piers sustain less lateral force and displacement. Then, the sectional member forces are well controlled in the intermediate piers by a proper application of the endrestraining abutments.