Abstract:As an important excitation source, track irregularities have a significant effect on the running safety and riding comfort of the high-speed train and bridge. A three-dimension train-track-bridge coupled dynamic model was established to study the effect of short-wavelength components of track irregularities on the dynamic responses of the train and 32 m simple supported box-girder bridge. Five different wavelength track irregularities were generated from German low interference track spectra in numerical method. The dynamic responses of train-track-bridge coupled system under different track irregularities were calculated. The results have shown that the 1 m short-wavelength component in track irregularities can significantly amplify the wheel-rail force, offload coefficient, derailment coefficient and the mid-span acceleration of the bridge. The mid-span displacement of the bridge, the wheel-rail relative lateral displacement and the car-body acceleration are less affected by the short-wavelength component of track irregularities. The main reason for the offload coefficient exceeding the code limits is 1~2 m short-wavelength components of track irregularities. The reduction of the short wavelength track irregularities component is effective in increasing the running safety.