某市轨道交通列车车厢内噪声水平调查与分析

Investigation and analysis on noise levels in metro carriages in a city

[背景]轨道交通(简称"轨交")列车运行时可产生较强的噪声,车厢内乘客噪声暴露水平的高低,不仅影响其乘坐的舒适性,更会对其心理和生理健康产生不同程度的影响。[目的]了解某市轨交列车车厢内噪声水平,探讨客流量和广播对车厢内噪声水平的影响。:00-1500,使用个体噪声剂量计分别对某市10条轨交线路列车车厢内噪声水平进行检测,分别计算每条轨交线路检测8 h全时段(7:00-15:00)、高峰时段(7:00-9:00)、平峰时段(9:00-15:00)、广播时段和无广播时段列车车厢内噪声等效声级。采用配对t检验比较高峰和平峰时段、广播和无广播时段列车车厢内噪声等效声级的差异。[结果]10条轨交线路检测全时段列车车厢内噪声等效声级的均值范围为74.6~80.9 dB(A)。高峰和平峰时段列车车厢内噪声等效声级的均值范围分别为74.7~81.1 dB(A)和74.4~80.8 dB(A),两者之间的差异无统计学意义(t=-1.564,P=0.125)。广播和无广播时段列车车厢内噪声等效声级的均值范围分别为74.2~80.7 dB(A)和74.7~81.2 dB(A),两者之间的差异无统计学意义(t=-1.640,P=0.102)。[结论]参考美国环境保护署和世界卫生组织推荐的噪声暴露限值标准,某市10条轨交线路在正常乘坐情况下发生听力损失的风险较低。客流量和广播对轨交列车车厢内噪声水平可能无实质影响。

[Background] A running metro train produces intense noise, which may not only reduce passengers’ comfort in carriages, but also adversely affect their psychological and physical health to varying extents. [Objective] This study is designed to assess the noise levels in metro carriages and explore the effects of passenger flow and station broadcast on the noise levels in a city.[Methods] The noise levels in the carriages of 10 metro lines in the city were measured with a noise dosimeter from 7:00 to 15:00 on weekdays from 15-28 November, 2018, and the equivalent continuous A-weighted sound pressure levels(LAeq) of total measuring time(8 h, from 7:00 to 15:00), peak(from 7:00 to 9:00) and off-peak(from 9:00 to 15:00) time, broadcast and nonbroadcast time were calculated for each line respectively. Paired t-test was applied to compare the LAeq between peak and off-peak time and between broadcast and non-broadcast time.[Results] The mean 8 h LAeq in the detected carriages of the 10 metro lines ranged from 74.6 to 80.9 dB(A). The mean LAeq of peak time and off-peak time were 74.7-81.1 dB(A) and 74.4-80.8 dB(A), respectively, and no significant difference was observed between the two time periods(t=-1.564, P=0.125). The mean LAeq of broadcast and non-broadcast time were 74.2-80.7 d B(A) and 74.7-81.2 dB(A), respectively, and no significant difference was observed between the two time periods(t=-1.640, P=0.102). [Conclusion] According to the exposure limit recommended by the US Environmental Protection Agency and the World Health Organization, the risk of hearing loss is relatively low for the passengers on the 10 metro lines in the selected city. Passenger flow and broadcast may not have substantial effects on the noise levels in metro carriages.