宁波轨道交通高架线综合降噪效果测试与分析

宁波轨道交通1号线一期工程高架线开展了无声屏障、全封闭声屏障、全封闭声屏障+梯形轨枕和全封闭声屏障+道床垫浮置式整体道床工况下的噪声对比测试试验.在各测量断面处布置7个噪声测点,并得到12.5～20000 Hz频段的噪声声压级与频谱曲线,分析各工况下噪声频谱特性与降噪效果.结果表明:仅采用全封闭声屏时,噪声源强处降噪效果最佳,且降噪效果随水平距离的增大呈衰减趋势;在全封闭声屏障的基础上采用梯形轨枕或道床垫浮置式整体道床后各测点(测点l除外)处降噪效果进一步增大,减振轨道确保了全封闭声屏障的降噪效果;减振轨道能有效减小桥梁结构噪声,但同时也增大了轮轨噪声;全封闭声屏障+道床垫浮置式整体道床的降噪效果优于全封闭声屏障+梯形轨枕.

Test and analysis on the noise reduction of Ningbo Rail Transit Elevated Line

Under the conditions of no sound barrier, fully-closed sound barrier, fully-closed sound barrier + ladder sleeper and fully-closed sound barrier +damping pad roadbed, noise test were carried out in the first stage of Ningbo rail transit line 1. There were 7 measuring points on each testing section. The sound pressure level and frequency spectrum curve of 12.5-20000 Hz were acquired, and the noise spectrum characteristics and noise reduction effect were analyzed under these conditions. The results show that when fully-closed sound barrier has been adopted, the noise reduction is biggest and the noise reduction increased with the horizontal distance attenuation trend. When fully-closed sound barrier + ladder sleeper or fully-closed sound barrier +damping pad roadbed have been adopted, noise reduction increased further in all measuring points except point 1, and the vibration damping track ensured noise reduction of fully-closed sound barrier. Vibration damping track reduced the bridge-structure noise and increases wheel-rail noise. Fully-closed sound barrier + damping pad roadbed was better than fully-closed sound barrier + ladder sleeper.