Research conclusions: The studies show the train speed has a significant impact on track structure vibrations．The sleeper vibration speed and the peak value of the reaction of monolithic track bed increase with the increase of the train speed．The track irregularity also has significant impacts on track vibrations．So the routine maintenances of rail wheels tread and rail surface are very important to reduce the track structure vibrations．In addition，the rigidity of rubber pad between sleeper and monolithic track bed has significant impact on track vibrations．The sleeper vibration speed decrease and the reaction of monolithic track bed increase with the increase of the rigidity of rubber pad，but the corresponding spectrum does not change．For the tunnel structure security，the rigidity of rubber pad should be decreased．