轨道交通地下站台低频结构噪声预测及其传播特性研究

该研究在对地下车站站台噪声现场试验及分析的基础上,通过对站台结构的精细化模拟,建立适用于站台结构振动辐射噪声分析的声场有限元模型,对轨道交通列车荷载作用下站台内低频结构噪声进行预测,分析了站台空间内低频结构噪声的声场分布特性,并从声模态的角度揭示了低频噪声传播机理。研究结果表明:地下站台低频噪声在50 Hz~85 Hz内存在显著峰值,主要来源于站台板的结构振动;低频结构噪声在站台不同平面位置的声压级水平表现出显著波动性,声压级大小在68.6 dB~80.4 dB,波动范围为12 dB;站台声腔敏感共振频率对低频结构噪声的影响显著,会显著放大车站低频结构噪声,改变声腔的高度可有效改善低频结构噪声对乘客的影响。

Prediction and propagation characteristics of structure-borne noise of an underground platform in rail transit

In this paper,noise field tests were carried out in an underground station platform.And a suitable finite element model was established to analyze structure-borne noise induced by the load of a rail transit train through the refined simulation of the station structure.The sound field distribution characteristics of low-frequency structure-borne noise in the station platform space were analyzed.At the same time,acoustic mode was used to reveal the propagation mechanism of low-frequency noise in the station platform.The analysis results indicate that:the low frequency noise in the underground station platform appears an obvious peak at 50 Hz-85 Hz,which is radiated mainly from the vibration of the platform board.The sound pressure level at different locations shows a significant volatility with a fluctuation of 12 dB,and the sound pressure level varies within 68.6 dB-80.4 dB.The sensitive resonant frequency of the platform acoustic cavity has a significant impact on low-frequency structural noise,which will amplify the low-frequency structural noise of the station.Changing the height of station platform is a useful method to improve the station sound environment.