奎屯河引水隧洞爆破粉尘监测与分析

Monitoring and analysis of blasting dust in Kuitun River diversion tunnel

隧洞爆破会产生大量的粉尘,对洞内设备、作业人员产生极大的危害,同时还会影响施工进度。本文分析隧洞爆破开挖条件下的粉尘浓度,以奎屯河引水隧洞爆破施工为背景,在洞内采用通风降尘条件下,监测得到掌子面后方75m、Ⅲ类Ⅳ类围岩、3m进尺和不同起爆药量下的PM25与PM10变化规律。结果表明:同为3m进尺,一次起爆药量减小了12kg,Ⅲ类围岩,PM25粉尘峰值浓度相对降低了约33%;Ⅳ类围岩,PM10粉尘峰值浓度相对降低了16%。在起爆药量相同的条件下,3m进尺,Ⅳ类围岩产生的PM25粉尘峰值浓度对比Ⅲ类围岩相对提高了90%。Ⅳ类围岩,一次起爆药量108kg的粉尘监测结果显示,PM10粉尘峰值浓度较PM2.5高出2.71mg/m3。基于隧道粉尘容许浓度最高标准,推测出试验区最迟将在监测结束4min后,达到容许浓度。研究成果为类似工程施工与隧道爆破粉尘控制提供指导。

Tunnel blasting produces a large amount of dust,which is great harm to the equipment and workers in the tunnelAt the same time,it affects the construction progress and analyze the dust concentration under the condition of tunnel blasting excavationTaking the blasting construction of the Kuitun River diversion tunnel as the background,under the condition of ventilation and dust suppression in the tunnel,the variation laws of PM2.5 and PM10 at 75 m,III class IV surrounding rock behind the tunnel face,3 m footage and different initiation charges are monitoredThe results show that for the same 3 m footage,the primary charge weight reduced by 12 kg,and the peak concentration of PM2.5 reduced by about 33%in class III surrounding rockClass IV surrounding rock,PM10 dust peak concentration reduced by about 16%Under the same condition of detonation charge and 3 m footage,the peak concentration of PM2.5 dust produced by class IV surrounding rock was 90% higher than that of class III surrounding rockIn the surrounding rock of class IV,the dust monitoring results of 108 kg primary explosive showed that the peak concentration of PM10 dust was 2.71 mg/m3 higher than that of PM2.5Based on the highest standard of allowable concentration of tunnel dust,it speculated that the test will reach the allowable concentration at least 4 min after the end of monitoringThe research results will provide guidance for similar engineering construction and tunnel blasting dust control。