Seismic behavior of typical isolated standard railway bridges and appropriate spectrum analysis methods
Based on three typical isolation systems,the structural seismic behavior of isolated standard rail-way bridges is primarily investigated with emphasis on dynamic effects of the pier mass and the influence of modes.The results show that the pier mass of standard railway bridges has a significant dynamic effect on the seismic response of piers.If the effect is ignored,the average relative error of pier top displacement and base bending moment reaches about 11％to 32％.But the influence on the displacement response of the girder is quite small with an average relative error no more than 5％.The seismic responses of the bridge pier of an isolated standard railway bridge is dominated by the first two modes in the analyzed direction.The second mode is characterized by vibration of the pier and its damping ratio can be safely considered in terms of the structural damping ratio.A SRSS combination of the responses of the first two modes could appropri-ately consider the dynamic effects of the pier mass and reduce the average relative error of the predicted base bending moment to 7.5％.Moreover,the multi-modes spectrum analysis method proposed by the AASHTO guidance is suitable for seismic analysis of typical isolated standard railway bridges.
standard railway bridgesfriction pendulum isolation bearingsteel damperdynamic effect of pier massspectrum analytical method
万方数据
维普
