城市轨道交通支承块式无砟轨道轮轨噪声研究

在已建立的轮轨噪声预测模型STTN的基础上，对城市轨道交通列车在支承块式无砟轨道上运行时的轮轨噪声进行了预测分析，并对城市轨道交通列车在支承块式无砟轨道上运行时产生的轮轨噪声与在有砟轨道上运行时的轮轨噪声进行了比较。列车以70km／h的速度运行时，轮轨噪声主要分布在中心频率约为500—2000Hz的范围内，其中钢轨辐射的主要是中、高频噪声，车轮辐射的主要是高频噪声，而支承块则辐射中、低频噪声。对总噪声贡献最大的是钢轨，而支承块及车轮的贡献几乎可以忽略。轮轨噪声随运行速度的增大而显著增大，其中车轮噪声受运行速度的影响最为显著，钢轨次之，支承块最小；在轨道旁，支承块式无砟轨道轮轨噪声比有砟轨道的大2．8—4．5dB（A），因此必须采取切实有效措施，将支承块式无砟轨道的轮轨噪声降到有砟轨道的水平甚至更低。

Study on Wheel/rail Noise for Elevated Block-Supported Track of the Urban Mass Transit

On the basis of wheel/rail noise prediction model called STTIN, characteristics of wheel/rail noise when a train running on an urban elevated block supported track, and wheel/rail noise of the block supported track is compared with that of the ballasted track. It makes clear that domain frequency of wheel/rail noise is in a range of 500- 2 000 Hz, and that the rail radiates chiefly middle and high frequency noise, and that the wheel radiates chiefly high frequency noise, and that the supporting block radiates noise in a range of middle and low frequency when the train run with a speed of 70 km/h. It is also known that the rail plays a far more important role than the wheel and the supporting block, and that wheel/rail noise is increased with the raise of running speed of the train, and that the influence of the speed on the noise radiated by the rail is more remarkable than that on the wheel and the supporting block. The wheel/rail noise of the block supported track is about 2.8 - 4.5 dB（A） higher than that of the ballasted track for the receiver nearby the rail. Measures should be taken to reduce the noise level of block - supported track down to the level of ballasted track or even lower.