摘要
认识瓦斯的迁移规律对于隧道瓦斯灾害防治至关重要。以梭萝坪隧道为例,综合现场实测和数值分析的方法,建立气-固耦合的瓦斯释放迁移二维有限元模型,求解隧道揭煤时瓦斯压力和瓦斯含量的时空演化规律,并针对高瓦斯隧道施工提出防治措施。结果表明,掌子面前方不同距离的瓦斯压力均呈单调非线性减小,且瓦斯压力的降低速度逐渐减小;瓦斯含量消散曲线随时间、空间的分布规律与瓦斯压力消散曲线基本一致,瓦斯从远距离煤层不断向掌子面附近运移;在掌子面附近,顶、底板和中部位置的瓦斯压力值相近且较小,在5 m位置处,瓦斯压力与初始瓦斯压力不断接近,其他位置处,顶板的瓦斯压力最大,底板次之,中心位置最小;瓦斯含量迁移曲线随空间的分布规律与瓦斯压力迁移曲线基本一致,在掌子面顶板和底板位置释放浓度明显大于中心位置;所提出的施工流程及防突施工措施,实现了隧道掌子面瓦斯压力、瓦斯含量的控制达标和隧道的安全高效生产。
Understanding the migration law of gas is crucial for the prevention and control of tunnel gas disasters.Taking the Suoluoping Tunnel as an example,a two⁃dimensional finite element model of gas solid coupling gas release and migration is established by combining on⁃site measurement and numerical analysis methods.The spatiotemporal evolution law of gas pressure and gas content during coal mining in the tunnel is solved,and prevention and control measures are proposed for the construction of high gas tunnels.The results show that the gas pressure at different distances in front of the tunnel face decreases monotonically and nonlinearly,and the rate of gas pressure reduction gradually decreases;the distribution pattern of gas content dissipation curve with time and space is basically consistent with the gas pressure dissipation curve,and gas continuously migrates from distant coal seams towards the vicinity of the working face;Near the tunnel face,the gas pressure values at the top,bottom,and middle positions are similar and relatively small.At the 5 m position,the gas pressure continuously approaches the initial gas pressure.At other positions,the gas pressure on the top plate is the highest,followed by the bottom plate,and the center position is the smallest;the distribution pattern of gas content migration curve with space is basically consistent with the gas pressure migration curve,and the release concentration is significantly higher at the top and bottom positions of the tunnel face than at the center position;the proposed construction process and anti⁃outburst construction measures have achieved the control of gas pressure and gas content on the tunnel face to meet standards,as well as safe and efficient production of the tunnel.
作者
孙瑞峰
SUN Ruifeng(China Railway 17th Bureau Group City Construction Co.Ltd.,Gui′an Guizhou 550025,China)
出处
《铁道建筑技术》
2024年第7期149-153,共5页
Railway Construction Technology
基金
中铁十七局集团有限公司科技研究开发项目(2023-B36)。
关键词
煤层瓦斯
隧道工程
迁移规律
瓦斯压力
揭煤
coal seam gas
tunnel engineering
migration patterns
gas pressure
uncovering coal
