CRTS III型板式无砟轨道桥梁段环境振动测试分析

为研究CRTS III型板式无砟轨道环境振动特点，对成灌铁路某桥梁段地面振动进行现场测试，分析不同测点地面振动加速度时程特点、频谱特征，并进行1/3倍频程分析和Z振级的衰减分析。结果表明，列车以180 km/h速度通过时，地面振动持续时间约6 s，距线路中心10 m处振动峰值加速度为60 mm/s2；在10 m处振动频谱分布范围在20～90 Hz，高频振动随距离衰减更快，大于20 m处振动主要以15～45 Hz为主；地面振动Z振级的衰减符合对数衰减规律。

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 10m 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.