NO .11-2 coal seam in Dingji coal mine has low gas permeability .Traditional Gas pre-drainage using cross hole has poor effect ,and control of coal and gas outburst always needs a long time . This leads to conflict between roadway excavation and coal mining .In order to increase efficiency of gas drainage ,decrease time of coal and gas outburst control ,and speed up roadway excavation ,a technology combining cave-digging using cross hole and deep-hole pre-splitting blasting was used to enhance gas permeability .Methane concentration of gas drainage was increased by 1 .65 times and gas flow increased by 1 .78 times .As a result ,efficiency of gas drainage was increased and the responding time was shortened . T he conflict betw een roadw ay excavation and coal mining w as solved ,and speed of safe roadw ay excava‐tion w as accelerated .%丁集矿11－2煤层透气性差，传统的穿层钻孔预抽煤层瓦斯效果差，煤层消突时间长，进而制约矿井采掘接替，为提高煤层瓦斯预抽率，实现煤层快速消突，从而达到煤巷快速掘进的目的，在丁集矿11－2煤层底抽巷采用穿层钻孔掏穴、深孔预裂爆破联合增透技术，底抽巷钻孔抽采数据表明，钻场平均瓦斯抽采浓度增大了1．67倍、平均瓦斯抽采流量增大了1．78倍，从而提高了瓦斯抽采率，缩短了抽采时间，解决了采掘接替紧张的难题，实现了煤巷安全、快速掘进。
展开▼
