基于轨道降噪措施的城市轨道交通噪声治理研究

Noise reduction in urban LRT networks by combining track based solutions

Quiet-Track项目的总体目标是为城市轻型轨道交通网络提供逐步缓解轨道噪声的措施以及铁路滚动噪声相关的维护方案,利用既有的各种轨道降噪措施及其组合达到≥6dB(A)降噪量的总体性能。在轮轨滚动噪声较高的雅典地铁1号线既有混凝土板式无砟轨道(RHEDA轨道)段进行了现场测试及验证工作。基于WRNOISE和IMMI噪声预测软件数值模拟对降噪措施方案进行优化比选,模拟计算了轮/轨噪声源强度与声源控制措施(如:磨削,轨道阻尼器,车轮阻尼器,车轮弹性的变化和/或钢轨固定),噪声传播特性与改变传播路径措施(如:轨道基座吸声,声屏障屏蔽等),以及更详细的降噪措施设计方案及可能的措施组合方案,并进行比较分析,确定了现有最佳降噪措施组合方案。模拟计算所需的轨道和车辆参数(例如,轨道和车轮粗糙度)由实验测试确定。为了在不影响轨道系统的正常运行的情况下有效降低滚动噪声,详细设计了三种不同的降噪措施:措施1:在道床上铺设预制吸声板(面板类型);措施2:设置高于轨面1.10~1.20m的吸声式声屏障;措施3:安装轨道减振器。选定的降噪措施均现场实施,并逐一测量其总体降噪性能与数值模拟计算进行比较。

The overall objective of the Quiet-Track project is to provide step-changing track based noise mitigation and maintenance schemes for railway rolling noise in LRT (Light Rail Transit) networks. WP 4 in particular focuses on the combination of existing track based solutions to yield a global performance of at least 6 dB(A). The validation was carried out using a track section in the network of Athens Metro Line 1 with an existing outside concrete slab track (RHEDA track) where high airborne rolling noise was observed. The procedure for the selection of mitigation measures is based on numerical simulations,combining WRNOISE and IMMI software tools for noise prediction with experimental determination of the required track and vehicle parameters (e.g.,rail and wheel roughness). The availability of a detailed rolling noise calculation procedure allows for detailed designing of measures and of ranking individual measures. It achieves this by including the modelling of the wheel/rail source intensity and of the noise propagation with the ability to evaluate the effect of modifications at source level (e.g.,grinding,rail dampers,wheel dampers,change in resiliency of wheels and/or rail fixation) and of modifications in the propagation path (absorption at the track base,noise barriers,screening). A relevant combination of existing solutions was selected in the function of the simulation results. Three distinct existing solutions were designed in detail aiming at a high rolling noise attenuation and not affecting the normal operation of the metro system:Action 1:implementation of sound absorbing precast elements (panel type) on the track bed,Action 2:implementation of an absorbing noise barrier with a height of 1.10~1.20 m above rail level,and Action 3:installation of rail dampers. The selected solutions were implemented on site and the global performance was measured step by step for comparison with simulations.