摘要
为解决非煤系地层瓦斯分布不均匀、逸出量和逸散规律在勘察期间难于探明和预测的问题,以兰海高速公路大土隧道为工程背景,采用人工监测与自动化监测的手段对掌子面的瓦斯浓度进行采集,分析瓦斯浓度随空间和时间的变化情况,并提出相应的施工防治措施。研究表明,爆破后比钻孔装药前、爆破前的瓦斯浓度显著增加,并且爆破的瓦斯浓度随监测次数的增加呈现先增加后减小的趋势;在隧道轴线方向上,瓦斯的逸出浓度明显受到岩性的影响,砂岩段的瓦斯浓度比泥岩、页岩段的大;在瓦斯的逸散速度上,砂岩掌子面比泥岩、页岩掌子面的瓦斯逸散速率大。
In order to solve the problems of uneven gas distribution and difficult to detect and predict the amount and law of gas escape in non-coal measure strata during the survey,taking Datu Tunnel of Lanzhou-Haikou Expressway as the engineering background,this paper collects the gas concentration in the tunnel face by means of manual monitoring and automatic monitoring,analyzes the change of gas concentration with space and time,and puts forward corresponding construction prevention measures.The research shows that the gas concentration after blasting is significantly higher than that before borehole charging and blasting,and the increase of monitoring times of gas concentration after blasting increases first and then decreases;in the direction of tunnel axis,the gas escape concentration is obviously affected by lithology,and the gas concentration in sandstone section is greater than that in mudstone and shale section;in terms of gas escape speed,the gas escape speed of sandstone face is higher than that of mudstone and shale face.
作者
郭宏伟
GUO Hongwei(China Railway 17^(th) Bureau Group City Construction Co.Ltd.,Gui’an Guizhou 550025,China)
出处
《铁道建筑技术》
2022年第5期143-147,共5页
Railway Construction Technology
基金
中国铁建股份有限公司科技研发计划项目(2019-C18)。
关键词
非煤系地层
瓦斯浓度
逸散规律
防治措施
non-coal measure strata
gas concentration
escape law
preventive measures
