Influence of Friction Effect of Sliding Bearings on Seismic Response of Continuous Beam Bridge

Abstract:

A variable crosssection prestressed concrete continuous girder bridge with a span of (55+4×90+55) m as the research object was analyzed, and the dynamic analysis model of the bridge was established by using the software ANSYS. Three artificial seismic waves were selected as seismic input. Based on dynamic nonlinear analysis method, the seismic response of the bridge and the hysteresis performance of the bearing considering friction effect for nonbrake piers were analyzed. Then, the seismic respose of the bridge considering friction effect was compared with that without considering friction effect. The results indicate that the basin rubber bearing at nonbrake pier has a regular and full hysteresis curve under seismic action, and the shape of the hysteresis curve is approximately rectangular. After considering the friction effect of the basin rubber bearing, the longitudinal bending moment and the shear force were reduced by 25.91% and 27.41% respectively at the bottom of nonbrake pier. The longitudinal displacement at the top of brake pier and the pierbeam relative displacement of nonbrake pier were reduced by 26.15% and 25.59% respectively. If the friction energy dissipation of sliding bearings is not considered for the multispan and longunit continuous beam bridge with multiple sliding bearings whose reaction force is large, the seismic response of bridge structure will be larger and the seismic design will be too conservative.