基于实测数据的典型高速铁路桥梁区段噪声对比

Noise Comparison of Typical High-speed Railway Bridge Sections Based on Measured Data

为掌握高速列车通过桥梁区段时的噪声特性,基于4座高速铁路桥梁(2座混凝土简支箱形梁桥、1座混凝土简支槽形梁桥和1座钢-混组合连续板梁桥)的噪声实测数据,对噪声频谱特性和空间分布规律,以及与梁型、车型和车速的关系进行分析和讨论。研究结果表明:高速铁路桥梁区段的路旁A计权声压级频谱曲线呈宽频特性,谱型为“中间高、两边低”,4座桥的共同显著频段为200~3150 Hz;在混凝土简支箱形梁区段,列车速度分别为120~200,200~300,320~385 km/h时,地面以上1.5 m、距外轨中心线25 m处的平均总声级分别为77.6,85.4 dB(A)和89.2 dB(A);混凝土槽形梁对轮轨噪声具有较好的降噪效果,但80 Hz以下频段的结构噪声比箱形梁更大;在400 Hz以下频段,钢-混组合梁的噪声远大于混凝土箱形梁,差值最大可达15.3 dB(A),故在减振降噪设计中应予以重点关注。

In order to explore the noise characteristics of trains passing over high-speed railway bridges,noise spectrum characteristics and spatial distribution laws,as well as the influences of bridge type,train type and train speed are analyzed and discussed based on field test noise data on four high-speed railway bridges(two concrete simply-supported box-girder bridges,one concrete simply-supported trough-girder bridge,and one steel-concrete composite continuous plate-girder bridge).Results show that the wayside A-weighted sound pressure levels(SPLs)for high-speed railway bridges exhibit broadband spectrum characteristics.The shapes of these SPL spectra show high magnitude in the middle and low magnitude on both sides.The consistent significant frequency band of SPLs for the four bridges is 200~3150 Hz.For the concrete box-girder bridges,when train speeds are respectively 120~200 km/h,200~300 km/h,and 320~385 km/h,the corresponding overall SPLs are 77.6,85.4,and 89.2 dB(A)at the location of 1.5 m above ground and 25 m from the center line of outer track.The concrete trough-girder has a good effect in reducing wheel-rail noise.However,The structure-borne noise of trough-girder is greater than that of box-girder in the frequencies below 80 Hz.The SPL of steel-concrete composite girder is much greater than that of the concrete box-girder below 400 Hz with a maximum difference up to 15.3 dB(A),which should be addressed in the design of vibration and noise reduction.