Dynamic Performance of High Speed Railway Box Girder with Shock Absorber

Based on the idea of "bearing function separation", a new kind of shock absorber is presented to reduce the seismic response of a bridge and to meet the demand of high speed train running. The finite element analysis on dynamic performances of box girders with the shock absorber under the train is given. The simply supported box girder bridge with different heights of piers is considered and its dynamic responses under earthquake excitations are analyzed. The results show that under the condition of the normal running of high speed train, the aseismic behavior of the bridges with the absorber can be greatly improved. The earthquake load transferred to the pier bottom of the bridge is reduced by over from 30% to 70%. By analysis and experiment research, it can be concluded that the absorber performs well in ductility and energy dissipation capacity at low cycle loading for a suitable range of bridge pier heights, and has a great stiffness at the elastic stage for normal running of high speed train.