With the methods of bridge structural dynamics and vehicle dynamics, regarding
high-speed trains and the long span cable-stayed bridge crossing over Yangtze river at Nanjing
in Beijing-Shanghai high-speed railway as a combined vibration system, the 3-dimensional
coupling vibration responses of the train and bridge are analyzed. The influences of the train
speed on bridge deflection, vehicle comfort quality and safety quality are studied. Results show
that, though the ratio of deflection-to-span under 0.8 UIC load is 1/600, high speed trains
can pass itwith satisfactory safety and comfort.