城市轨道交通高架桥结构噪声声场分布及传播规律研究

对安装有全封闭声屏障的城市轨道交通高架桥及沿线进行噪声测试,并对测试结果的频域和声场分布进行分析。结果表明:桥梁结构噪声以低频为主,峰值出现在50~80 Hz频段范围内;腹板和翼板近场噪声频谱特性基本一致,底板近场噪声总声压级最大,但某些频段声压却较小;桥梁结构噪声总体上随着横向距离增大而逐渐衰减,但局部由于干涉作用出现随着距离增大频段声压反而增大的现象;在地面反射波的作用下,声场沿垂向呈现出复杂的变化规律,且地面反射对远场近地面噪声影响较大。

Distribution and Propagation Law of Structural Noise Sound Field on Urban Rail Transit Viaduct

The noise fields along urban rail transit viaduct e-quipped with fully enclosed sound barriers are tested,the test results of frequency domain and sound field distribution are analyzed,which show that the structural noise of viaduct is mainly in low-frequency,and the peak band is within the scope of 50 ～ 80 Hz. The characteristics of near field noise spectrum of the web and the wing plate are generally identical, the overall sound pressure level of near field noise on base plate is the highest,but the sound pressure in some bands is smaller. Because of interference effect in some sections,the structure noise gradually decreases with the increase of the transverse distance,but the sound pressure of frequency band increases with the increase of distance. With the effect of ground reflected wave,the noise field presents a complex change along the vertical direction,and the ground reflection has a greater influence on the near ground sites.