昌景黄铁路隧道瓦斯地质特征与危险性评价  

Tunnel Gas Geological Features and Hazard Assessment during Nanchang-Jingdezhen-Huangshan High-speed Railway Construction

作　　者：巩书华 张良平 蔡宁波 申建平 Gong Shuhua;Zhang Liangping;Cai Ningbo;Shen Jianping(Hunan Coal Geological Exploration Institute,Changsha,Hunan 410014;Hunan Geological New Energy Exploration and Exploitation Engineering Technological Research Center,Changsha,Hunan 410014)

机构地区：[1]湖南省煤炭地质勘查院,长沙410014 [2]湖南省地质新能源勘探开发工程技术研究中心,长沙410014

出　　处：《中国煤炭地质》2021年第6期42-46,共5页Coal Geology of China

基　　金：湖南省地质院科研项目(201910)。

摘　　要：隧道瓦斯是影响隧道施工的重要危险因素,拟建昌景黄铁路施工隧道穿越皖南地区寒武系荷塘组与杨柳岗组炭质泥岩与石煤层优质含气层,存在一定瓦斯突出安全隐患。通过对该区隧道瓦斯地质特征分析,认为区内高演化程度含气层有机碳含量较高,石煤层属高灰、中—高磷、高硫、低热值燃料,具备良好生烃物质基础;但隧道瓦斯浓度与压力测试结果均较低,气体组分以氮气与氧气为主,瓦斯突出危险性与石煤尘爆炸性较低,隧道建设施工中瓦斯危害可控;隧道揭露石煤层属Ⅱ类(自燃)—Ⅲ类(不易自燃)等级,由于自燃周期较长且隧道施工护壁工作及时,隧道内石煤层自燃的可能性极低。分析认为区内隧道瓦斯含量较低的原因主要是含气层保存条件差、瓦斯赋存的垂直分带性影响、地下水活动加速瓦斯逸散以及烃源岩热演化程度过高。Tunnel gas is an important hazardous factor impacting tunnel construction.The proposed Nanchang-Jingdezhen-Huangshan high-speed railway tunnels should pass through Cambrian Hetang and Yangliugang formations high-quality gas-bearing zone carbargillite and stone-like coal in southern Anhui,thus has certain gas outburst potential safety hazard existed.Through analysis of tunnel gas geological features has considered that organic carbon content is rather high in gas-bearing zone with high degree of evolution in the area.Stone-like coal is a kind of high ash,medium-high phosphorus,high sulfur and low calorific fuel with favorable hydrocarbon generation material basis.However,tested results of tunnel gas concentration and pressure are rather low;gas composition is mainly nitrogen and the risk of gas outburst and stone-like coal dust explosiveness are low,thus gas hazard is controllable during tunnel construction.Tunnel revealed stone-like coal belongs to categories II(spontaneous combustible)and III(not easy to spontaneous combustible),due to rather long spontaneous combustion cycle,and timely wall protecting works in tunnel construction,tunnel stone-like coal spontaneous combustion possibility is very low.The analysis has considered that the causation of tunnel gas content rather low is from poor gas-bearing strata preservation conditions,impact from gas hosting vertical zonality,groundwater activities speed up gas dissipation and source rock thermal evolution degree too high etc.

关 键 词：瓦斯地质特征 铁路隧道 危险性评价 昌景黄铁路 

分 类 号：U455[建筑科学—桥梁与隧道工程]