地铁高架箱型梁正下方噪声辐射特性试验分析

Test and Analysis of Noise Radiation Characteristics below the Metro Viaduct Box Girder

为了研究地铁高架箱型梁正下方噪声辐射特性,以宁波地铁1号线为例,进行现场测试,并对噪声数据进行1/3倍频程分析,特征频率下的线性声压级时域特性分析及线性声压级对比分析。结果表明,各测点在不同车次列车通过时,均在50~80Hz频率范围内取得全频段峰值,且箱型梁底板处测点的峰值最大;各测点在列车通过时,线性声压级曲线的波动范围很相近,且存在一定的交错;在低频0~50Hz范围内,噪声主要分布于箱型梁桥下空间的底部;在中低频80~630Hz范围内,噪声主要分布于箱型梁底板附近。

In order to study the noise radiation characteristics of the metro box girder, taking Ningbo Metro Line 1 as an example, field test was carried out. The noise data was analyzed from three aspects, the 1/3 octave analysis, the time domain analysis of linear sound pressure level characteristic frequencies and the comparison analysis of linear SPL of measuring points. The results show that when the train passes, the peak value is reached in the 50 - 80Hz frequency range, and the peak value of the measuring point in box girder floor is the largest. The fluctuation range of the linear sound pressure level curves is very close, and there is a certain degree of interleaving. The low frequency noise of 0 - 50Hz is mainly distributed at the bottom of the space under the bridge. In the range of 80 - 630Hz, noise is mainly distributed near the bottom plate of the box girder.