对高架桥无声屏障断面及有全封闭声屏障断面进行对比试验;分析了两断面总体的噪声频谱特性及声压级1/3倍频程;并从两断面中选取了高度相同的2对测点,进行了噪声频谱特性及声压级1/3倍频程分析.结果表明,全封闭声屏障对高架桥噪声辐射在全频段的降噪效果明显,但在低频段所起的作用有限;安装全封闭声屏障后的测试断面,噪声成分以低频为主;从频率方面看,全封闭声屏障让低频噪声波峰数量明显增多;全封闭声屏障可以降低声压级1/3倍频程峰值大小,但不会改变峰值频谱分布特性.%Conduct comparison experiment for silent protective screen cross section and totally closed a-coustic barrier cross section of overpass;analyze total noise spectrum and one thirds of octave of SPL for both sections;select two pairs of measuring points with same height from them to analyze noise spectral characteristic and SPL one thirds octave.The result showed that totally closed acoustic barrier has evident anti-noise effect in full-band on overpass,with little effect in low-frequency stage.With totally closed acous-tic barrier,the noise in tested section mainly included low frequency;from frequency,totally closed acoustic barrier makes number of low-frequency noise wave crest increased;totally closed acoustic barrier can re-duce peak value of SPL one thirds frequency multiplications,but can′t change distribution character of peak spectrum.
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