DYNAMIC RESPONSES OF LONG SPAN CONTINUOUS STEEL TRUSS ARCH BRIDGE UNDER RUNNING HIGH-SPEED TRAIN

摘要

A dynamic analysis model of train-bridge system subjected to cross winds is established in this paper. The dynamic interaction model of the train-bridge system is established. The wind excitations of the bridge are static, buffeting and self-excited forces, while the wind loads on the train vehicles are static and buffeting forces, in which the self-exciting force is neglected. The wind load and the track irregularities are taken as the system excitations. The framework is then applied to the main bridge of Nanjing Yangtze-River Bridge which is 6-span continuous steel truss arch bridge with 108+192+336+336+192+108m span. The dynamic responses of the bridge and the vehicles in cross winds are calculated. The influences of train speed and wind velocities on the dynamic responses of the train-bridge system are studied. The critical trains speeds are proposed for running safety on high-speed railway bridges in cross winds with different mean wind velocities.