高速铁路隧道与明线段噪声影响对比分析

Comparative Analysis of High-speed Railway Noise around Tunnel and Open-line Section

测试设计时速350 km高速铁路隧道与明线路基段噪声,获得动车组进出隧道时噪声与路基区段噪声时频特性差异,分析认为导致差异产生的主要影响因素包括隧道混响声、噪声沿隧道的传播、隧道壁对噪声的遮挡、隧道对气动声源的影响等。试验结果表明:动车组在隧道内时有较高噪声传出洞口,宜采用暴露声级评价隧道洞口与明线段噪声差异;隧道洞口声环境恶化主要由动车组驶出隧道引起,暴露声级高出路基区段约2 dB(A),驶入隧道时暴露声级与路基区段相差较小。

The noise of the tunnel and subgrade section of a high-speed railway with the design speed of 350 km/h was tested,and the difference in time and frequency characteristics between the noise of EMUs entering and leaving the tunnel and the noise of subgrade section was obtained.Analysis showed that the main influencing factors include tunnel reverberation,noise propagation along the tunnel,shielding of the tunnel wall,and the impact of the tunnel on the aerodynamic sound sources.The test results showed that when the EMU was running in the tunnel,there was already high noise emitted from the tunnel portal,and therefore the Sound Exposure Level(SEL)was a better index to evaluate the impact of tunnel noise.The deterioration of the acoustic environment around the tunnel portal was mainly caused by the EMUs driving out of the tunnel,which was about 2 dB(A)higher than the subgrade section,while the SEL of EMUs entering the tunnel was almost the same with the subgrade section.