INFLUENCE OF PIERS ON DYNAMIC RESPONSE OF TRAIN-BRIDGE SYSTEM SUBJECTED TO SEISMIC EXCITATIONS

The dynamic model of train-bridge system under earthquakes is established. The multi-span simply-supported railway bridges on existing railway line in China are analyzed. By using the computer simulation method, the whole histories of the trains running on the bridges subjected to typical earthquake waves are simulated, and the dynamic responses of the bridge and the trains are calculated. The influence factors on dynamic response of train-bridge system such as section shapes, height, natural frequency and lateral rigidity of the piers are studied in detail. According to the safety evaluation indices in the Current design code for railway bridges in China, the critical running speed limits insuring trains running safely on the bridge during earthquakes are obtained. The parameters for assessing reasonable aseismatic bridge piers are proposed preliminarily.