摘要
为揭示突出煤层群多次采动对底抽巷穿层钻孔瓦斯抽采效率的影响,利用Flac软件模拟分析沙曲二矿3、4、5号煤层下行开采过程中底抽巷顶板煤岩层卸压特征和围岩塑形区扩展特征,并现场实测钻孔瓦斯抽采效率。研究表明:3号煤层采动引起底抽巷顶板煤岩层卸压程度达59%以上,卸压作用最为显著,对钻孔瓦斯抽采浓度与抽采纯量的提升幅度最大;随着采动叠加作用影响,卸压程度减小,提升幅度也减小;4号煤层开采期间底抽巷顶板围岩塑性区范围扩张达到3.1 m,超过钻孔封孔长度,钻孔瓦斯混量开始逐渐增大,随采动次数增加,顶板围岩塑性区范围进一步扩展,钻孔瓦斯混量呈现逐步增大趋势;多次采动作用下钻孔瓦斯抽采体积分数和抽采纯量总体上呈逐渐下降趋势。
In order to reveal influence of multiple mining of coal seam group on gas extraction efficiency of cross-layer borehole in bottom extraction roadway,Flac software was used to simulate and study pressure relief characteristics of roadway roof and expansion features of plastic area of surrounding rock during downward mining of No.3,4,5 coal seam of Shaqu No.2 mine.Then,site measurement was conducted for borehole gas extraction efficiency.The results show that pressure relief degree of No.3 coal seam mining is more than 59%,indicating the most obvious pressure relief effect and largest increase rate of gas extraction concentration and purity.Along with increase of mining times,pressure relief degree and increase rate decrease.During mining of the No.4 coal seam,plastic area of surrounding rock reaches3.1 m,exceeding borehole sealing length,and amount of gas mixture in borehole begins to increase gradually.As mining times increase,plastic area and gas mixture increase.Meanwhile,gas extraction concentration and purity of cross-layer borehole show a gradual downward trend.
作者
杨正凯
程志恒
刘彦青
王宏冰
杨鹏
孙福龙
YANG Zhengkai;CHENG Zhiheng;LIU Yanqing;WANG Hongbing;YANG Peng;SUN Fulong(China Coal Research Institute,Beijing 100013,China;School of Energy and Mining Engineering,China University of Mining&Technology,Beijing 100083,China;School of Safety Engineering,North China Institute of Science and Technology,Beijing 101601,China;Huake Zhongan Technology(Beijing)Co.Ltd.,Beijing 102300;Mine Safety Technology Branch of China Coal Research Institute,Beijing 100013,China;Shaqu No.2 Mine of Huajin Coking Coal Co.,Ltd.,Liulin Shanxi 033000,China)
出处
《中国安全科学学报》
CAS
CSCD
北大核心
2020年第5期66-73,共8页
China Safety Science Journal
基金
国家重点研发计划项目(2017YFC0804206)
国家科技重大专项(2016ZX05067-005)
中央高校基本科研业务费项目(3142019005)。
关键词
煤层群
下行开采
穿层钻孔
卸压瓦斯
抽采效率
coal seam group
downward mining
cross-layer borehole
pressure relief gas
extraction efficiency
