摘要
地下浅层有害气体是影响地下交通工程施工与后期运营的重要危险因素,对其地质成藏特征的研究可有效指导治理措施的设计部署。以昆明地铁2号线工程为例,通过对工程中有害气体喷发重点区段现场勘察与实验分析,研究分析了浅层有害气体成藏特征。该工程区段地下浅层有害气体是赋存于第四系泥炭质土层中以甲烷组分为主的小型、低压生物气。含气层空间分布特征显示,福保路段揭露两层含气层中的下部含气层与地铁结构线为纵贯关系,施工危险性较大;而该段上部含气层以及官南路段含气层均不与地铁结构线交叉,危险性较小。尽管由于前期工程施工导致勘察区段地下有害气体压力与流量降低,但不排除勘察区间或周边存在小型高压气体聚集区的可能性,故建议在施工过程中要对地下有害气体进行同步探测,对于高压气层采取提前排气与压入式机械通风处理措施,同时加强现场有害气体监测。
The shallow underground harmful gas is an important risk factor affecting the construction and later operation of underground transportation projects.The study of its accumulation characteristics can effectively guide the design and deployment of treatment measures.Kunming Metro Line 2 project was taken as an example in this paper,and the characteristics of shallow harmful gas accumulation was analyzed through field survey and experimental analysis of the key sections of harmful gas eruption in the project.The harmful gas in the shallow underground layer of the project section is a small,low-pressure biogas mainly composed of methane that occurs in the Quaternary peaty soil layer.The spatial distribution characteristics of the gas-bearing zone show that the lower gas-bearing zone of the two gas-bearing zones in the Fubao section is longitudinally connected to the subway structure line,and the construction risk is greater,while the upper gas-bearing zone of this section and the Guannan section is diverged with the subway structure line,and the danger is small.Although the pressure and flow rate of the underground hazardous gas in the survey section have been reduced due to the preliminary construction,the possibility of small high-pressure gas accumulation areas in the survey area or the surrounding area is not ruled out.Therefore,it is recommended that the underground hazardous gas be detected simultaneously during the construction process.For the high-pressure gas layer,the measures of pre-exhaust,press-in mechanical ventilation and monitoring of harmful gases on site should be taken and strengthened.
作者
巩书华
蔡宁波
刘治宇
韩征
申建平
张良平
GONG Shu-hua;CAI Ning-bo;LIU Zhi-yu;HAN Zheng;SHEN Jian-ping;ZHANG Liang-ping(Hunan Institute of Geophysical and Geochemical Survey,Changsha 410014,China;Geological New Energy Exploration and Development Engineering Technology Research Center of Hunan Province,Changsha 410014,China;School of Civil Engineering,Central South University,Changsha 410075,China;State Key Laboratory of Geohazard Prevention and Geo-environment Protection,Chengdu 610000,China)
出处
《科学技术与工程》
北大核心
2022年第26期11630-11637,共8页
Science Technology and Engineering
基金
国家重点研发计划(2017YFB1201204)
国家自然科学基金(41702310)
湖南省自然科学基金(2018JJ3644)
地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2017K014)
湖南省地质院科研项目(201910)。
关键词
浅层有害气体
成藏特征
超前排气
地铁隧道
昆明轨道交通
shallow harmful gas
accumulation characteristics
press-in mechanical ventilation treatment
subway tunnel
Kunming rail transit
