Measurement and Analysis of Environmental Vibration in Railway Bridge Section of CRTS III Slab Ballastless Track

To study the environmental vibration characteristics of CRTS III slab ballastless track, the ground vibration test is carried out in a bridge section of Cheng-Guan high-speed railway. The time-history characteristic and frequency spectrum feature of the ground vibration acceleration are analyzed at different measurement points. The one-third octave vibration and the decay of the Z vibration level are also analyzed. Results of measurement and analysis indicate that the ground vibration duration is about 6 seconds when train running at speed of 180 km/h. The peak acceleration at 10 m distance from central line of the track is 60 mm/s2, and the vibration frequency spectrum there is distributed in the range of 20-90 Hz. Vibration of high frequency attenuates faster than low frequency vibration with the distance increasing. In the location with the distance from the central line of the track larger than 20 m, the vibration mainly consists of 15-45 Hz frequencies. Attenuation of the Z vibration level of the ground vibration can match the law of logarithmic decrement.