城市轨道交通列车在高架桥上运行,会对沿线区域产生噪声辐射.针对这一问题,首先对城市轨道交通高架桥近场噪声辐射与远场噪声辐射进行了现场试验;然后进行了频域分析及1/3倍频程频谱分析,得到了高架桥近场及远场噪声辐射特性分布;最后对近场及远场的噪声A计权总声压级进行了对比分析,得到了总声压级沿高度分布特性.结果表明,中频、高频噪声辐射随距离衰减较快,而低频噪声辐射随距离衰减较慢;在近场,与桥梁等高处A计权总声压级最大,在远场,近地面的A计权总声压级最大;在近场与远场,A计权总声压级在高度方向上的分布具有明显区别.%When the urban rail transit train runs on the viaduct, it will produce noise radiation along the area.In view of this problem, it carries out the field test of rail transit viaduct in near-field noise radiation and far-field noise radiation,obtains the frequency-domain analysis and 1/3 octave spectrum analysis and finds the viaduct noise radiation characteristics distribution in near and far field.Comparing a weighted sound pressure level of the near field noise with far field noise, it gets the total sound pressure distribution along the height.The results show that the medium-frequency noise and high-frequency noise attenuate with distance is fast, but the low-frequency noise radiation attenuate with distance is slow.In the near field, a weighted maximum sound pressure level is maximum at the bridge height;in the far field, a weighted maximum sound pressure level is maximum near the ground.In the near and far field, the distribution of the weighted sound pressure level has great difference in the height direction.
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