[关键词]
[摘要]
针对城市轨道交通地上线运营引起的噪声污染问题,以郑州地铁5号线中州大道车辆段出入线为工程实 例,对加装声屏障前后的噪声进行现场测试,采用Virtual Lab软件对声屏障的降噪过程进行仿真模拟,仿真模拟 与实测声压级随声源频率的变化曲线具有较好的吻合性,验证了声学仿真模型与计算方法的准确性。采用声压级 插入损失表征声屏障的降噪效果,进一步研究三角尖劈型、QRD序列和PRD序列、微穿孔板-PRD I型复合结构 等类型声屏障的降噪效果。结果表明:尖劈角度对三角尖劈型声屏障降噪效果的影响较为显著;较高不规则度有 利于提高PRD型声屏障对绕射声的扩散作用,降噪效果比QRD型声屏障更佳;PRD I型声屏障的整体降噪效果 略高于PRD Ⅱ型声屏障,适当降低扩散体设计频率、增加阶数和扩大槽宽均能提升PRD I型声屏障的降噪效果; 在微穿孔板-PRD I型复合声屏障扩散体端部凹槽中添加微穿孔板共振吸音结构,能进一步提高扩散体端部结构的 降噪增益,对改善地铁出入线噪声环境具有理想的应用前景。
[Key word]
[Abstract]
Concerning the noise pollution caused by the operation of the ground line of urban rail transit, the access line of the Zhongzhou Avenue depot in Zhengzhou Metro Line 5 is taken as an engineering example. The noise is tested in situ before and after the installation of sound barriers, and the noise reduction process is simulated with Virtual Lab software. The simulation results are in good agreement with the tested sound pressure level changing with the sound source frequency, and the accuracy of the acoustic simulation model and calculation method is verified. The insertion loss of sound pressure level is adopted to characterize the noise reduction effectiveness of the sound barrier, and further research are conducted on the noise reduction effectiveness of triangular wedge, QRD (Quadratic Residue Diffuser) sequence, PRD (Prime Root Diffuser) sequence and micro perforated panel - PRD I composite sound barrier, and the results reveal that the wedge angle significantly impacts the noise reduction effectiveness of the triangular wedge sound barrier; greater irregularity enhances the diffusion effect for diffracted sound in PRD sound barriers, and PRD sound barriers exhibit better noise reduction effectiveness than QRD sound barriers; the overall noise reduction effectiveness of PRD type I sound barrier is slightly higher than that of PRD type II sound barrier, to reduce appropriately the design frequency of the diffusion body, increase the order, and expand the slot width can advance the noise reduction performance of the PRD type I sound barrier; to add micro perforated plate resonance sound absorption structure in the diffuser end groove of micro perforated panel - PRD I composite can further improve the noise reduction of the end structure of diffuser, which would have an ideal application prospect for improving the noise environment of metro access lines.
[中图分类号]
U231
[基金项目]
国家自然科学基金(51278467),中国铁道科学研究院基金项目(2022YJ280),河南省科技攻关(242102240019)