TRAFFIC-INDUCED VIBRATION AND SEISMIC RESPONSES OF CURVED GIRDER BRIDGES UNDER VEHICLE LOADINGS

to investigate effects of moving vehicles on the dynamic responses of curved girder bridges as well as effect of seismic input directions and vehicle loadings on the seismic response of curved girder bridges by means of a three-dimensional dynamic analysis considering the bridge-vehicle interaction. The dump truck is modeled as a discrete rigid multi-body system with 12 degrees of freedom. A probable cause of failure of tension bolts at the movable support of a curved box-girder bridge is analytically examined. Observations show that big uplift forces occur at the movable support of which two bolts had broken from traffic vibration analysis and seismic response analysis. The existence of heavy vehicles can increase or decrease seismic responses of the curved bridge according to the attack angle of earthquakes. The most severe reaction forces were obtained by the analysis utilizing the model without considering vehicles.