Effects of Friction at Movable Supports on Elasto-Plastic Seismic Responses of Continuous Girder Bridges

Abstract

The effect of friction at movable supports on the elasto-plastic seismic responses of continuous girder bridges was analyzed on the basis of three aspects including stiffness contribution, friction energy dissipation of the movable supports, and kinetic interaction between the girders and movable piers. Finite element models were established, which considered the friction non-linearity of the movable supports and the material nonlinearity of the reinforced concrete piers. In addition, nonlinear time history analysis was performed to analyze the effects of friction at the movable supports on the pier bottom curvature, girder displacement, velocity, and acceleration. The results indicated that the frictional effect at movable supports is not always favorable. In some cases, the friction at these points must be considered. For the nonlinear time history analysis, the effect of natural vibration characteristics of the bridge and the response spectrum of the ground should also be considered. For some complicated continuous bridges, particularly those with the heights and stiffness of the fixed and movable piers, the friction at movable supports should be considered in seismic analysis.