管片接缝对地铁振动源强影响现场测试研究

Field testing and analysis of the influence of segment joints on metro vibration source intensity

地铁振动源强的选取是开展环境振动评估的核心环节。目前,地铁盾构隧道普遍采用管片拼接方式,在进行振动源强测试时存在跨越管片接缝和不跨管片接缝2种情况,文章通过现场行车测试和锤击试验,研究管片接缝对振动源强的影响效果和振动传递特征。结果表明:对于最大Z振级评价,全天车次最大Z振级差值统计结果的平均值为0.77 dB,最大值为2.22 dB;对于典型工况分频最大振级评价,Z计权前分频最大振级在200 Hz频率处,测点1和测点2的差值为3.44 dB,Z计权后分频最大振级在50 Hz频率处,测点1和测点2的差值为0.45 dB;管片接缝在141~346 Hz和410~502 Hz频率段具有振动减小作用。相关研究可为地铁振动源强测点选择提供参考。

The selection of metro vibration source intensity is the core link of environmental vibration assessment.At present,the method of segment splicing is commonly used in metro shield tunnels,and there are two cases of vibration source intensity testing,namely across the segment joints and not across the segment joints.This article investigates the impact of segment joints on vibration source intensity and vibration transmission characteristics through on-site driving tests and hammering tests.The results show that:For the evaluation of Z-weighted maximum vibration level,the average value of the statistics of all day trains is 0.77 dB,with a maximum value of 2.22 dB.For the evaluation of the maximum vibration level at different frequencies under typical operating conditions,before Z-weighting,the maximum vibration level appears at 200 Hz,with a difference of 3.44 dB for measurement points 1 and 2.After Z-weighting,the maximum vibration level appears at 50 Hz,with a difference of 0.45 dB for measurement points 1 and 2.The segment joint has a vibration reduction effect in the frequency range of 141~346 Hz and 410~502 Hz.The relevant study could provide reference for the selection of measurement points for metro vibration source intensity testing.