高架轨道交通噪声的分析与控制技术研究

轨道交通是大城市公共交通方式的首选,其产生的噪声可能污染沿线地区的环境,高架轨道交通噪声的分析、预测和控制成为建造高架轨道交通必须解决的问题。首先用传声器阵列分析了上海轨道交通9号线列车噪声级沿高度的指向性,研究了各1/3倍频程对总噪声的贡献量,归纳了列车等效声功率级与列车速度的关系。然后建立了一套适用于高架轨道交通噪声辐射的预测模型,将列车视作一个移动的均匀线声源,采用单极子和偶极子传播模型拟合轻轨列车的通过噪声,并用高架轨道交通线附近的测量数据,验证了不同测点情形下模型的适用性,为预测高架轨道交通线的噪声辐射提供了一种实用方法。最后,介绍了新开发的道间声屏障和动力吸振阻尼钢轨技术,以及工程应用效果。

Analysis and reduction techniques for noise of lifted railway transportation

Railway transportation can be considered as the first public transportation system in big cities, but it generates noise that may pollute the environment along railway line. The analysis, prediction and reduction of the noise become key techniques in building urban lifted railway transportation lines. The sound level and radiation pattern of the noise from the trains running on Shanghai No. 9 urban railway are investigated by microphone arrays, and the contribution of each 1/3 octave spectrum is evaluated. The relations of equivalent sound power level with train speed are obtained via analyzing experimental results. A model is suggested to predict the noise radiation from urban lifted railway as the train is considered to be a linear source in uniform motion. The monopole models and dipolar models are employed for analyzing the pass-by noise of urban railway trains. The models are verified by the data measured along the lifted railway area, and the applicability of the model in different cases is studied. It is shown that the model can be used to predict the noise radiated from lifted railway transportation. Finally, a new kind of dynamic absorber damping track and acoustic barriers between tracks are recommended, and with which the effects of noise reduction in engineering are demonstrated.