地下站台内轮轨滚动噪声的传播特性及其降噪措施

Analysis of Propagation Characteristics and Noise Reduction Measures on Underground Platform from Wheel-Rail Rolling Noise

摘要:

为分析轮轨滚动噪声作用下地下站台的声场特性，基于几何声学法建立了全尺站台三维声学仿真模型，首先利用有限元-边界元法计算得到了列车进站时引起的轮轨滚动噪声，并以此作为地下站台声学仿真模型的声源输入，研究了轮轨滚动噪声作用下地下车站站台内的声场分布及传播特性。在此基础上，进一步分析了轨行区吸声材料的敷设位置及敷设长度对站台区降噪效果的影响规律。研究表明，①列车驶入站台过程中，站台噪声最显著区域为进站端靠行车侧距站台门6m范围内，沿站台纵向及横向逐渐减小，至出站端轮轨滚动噪声的影响较小，其中列车1节车厢进入车站范围时站台区噪声最大，进站端A计权声压级最大值达到83.1 dB（A）；②在轨行区站台板下部墙面及侧墙面同时敷设砂岩吸声板可取得较好的降噪效果，站台区进站端降噪量可达到2.9~5.3dB（A）；③将吸声材料的敷设范围沿站台两侧延伸10m至隧道区间内，站台区进站端的降噪量可提高至6.1~7.9dB（A），尤其是当列车靠近站台但仍运行于隧道内时，但继续延长敷设长度对站台区降噪效果的提高不明显。

Abstract:

In order to analyze the sound field distribution of subway underground platform from wheel-rail rolling noise， a three-dimensional full-length acoustic model of platform was established based on the geometric acoustic method. The wheel-rail rolling noise while the train was passing was calculated using the finite element method and boundary element method and it worked as the source of the platform acoustic model. The sound field distribution and propagation characteristics of the platform from wheel-rail rolling noise were studied.Based on which， the noise reduction effect of using sound-absorbing materials was analyzed， including the laying positions and lengths of absorbing materials. The results show that with a train entering， the most notable regions of noise on the platform are at the train-arriving end and 6m away from the platform gate of the passing side in lateral， and the noise is gradually reduced along longitudinal and lateral. The effect of rolling noise on the train-leaving end is small. The noise on the platform is most remarkable when only one train pulls into the station. The A-weighted overall sound pressure level reaches 83.1dB （A）. Besides， the cases that sound-absorbing materials covered both on the vertical wall of the niche under platform and side wall opposite the platform alongside the track area can achieve a good noise reduction effect. The noise reduction at the platform train-arriving end can reach 2.9~5.3dB （A）. Moreover， the noise reduction at the platform train-arriving end can reach 6.1~7.9dB （A） with the sound-absorbing materials laying area extending into the tunnel about 10m， especially when the train is near the platform but still in the tunnel. But the effect will not be improved obviously if the laying length continues to be extended.