采空区瓦斯宏观流动通道的高位钻孔抽采技术  

Highly-located boreholes drainage technology of gas macroscopic flow channel in goaf

作　　者：李春元[1] 张勇[1] 李佳[1] 张国军[1] 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《采矿与安全工程学报》2017年第2期391-397,共7页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2016YFC0600708);国家重点基础研究发展计划(973)项目(2011CB201204);中央高校基本科研业务费专项资金项目(2011YZ05)

摘　　要：采场顶板来压极易将采空区内瓦斯压出引发上隅角瓦斯超限甚至瓦斯爆炸。基于岩体的尺寸及时间效应分析了采空区瓦斯宏观流动通道的演化发育规律,应用离散元数值软件计算了顶板来压前后瓦斯宏观流动通道的变化,结合关键层理论研究了基于顶板来压影响及瓦斯宏观流动通道变化的高位抽采钻孔终孔位置、钻场间距及钻孔接续的确定方法及设计技术。结果表明:采空区基本顶载荷作用时间越长,垮断距越大,岩层裂隙越发育;顶板来压及接近来压时瓦斯宏观流动通道最为发育,贯通性最好,其水平裂隙宽度是来压前的3倍,最利于瓦斯抽采。现场应用来压时抽采效率提高约55%,避免了瓦斯超限。Roof weighting in the working face can easily press gas out of the goaf and cause the gas at the upper comer to exceed its concentration limits or even set off gas explosion. Based on size and time effect of the rock mass, the evolution and development law of gas macroscopic flow channel in the goaf was analyzed： the change of the macroscopic flow channel before and after roof weighting was worked out with the numerical software of distinct element; combining with key strata theory of rock control, the layout method and design technology of end borehole position, drilling field spacing and the fol- lowing boreholes for highly-located gas drainage boreholes under the roof weighting influence and change of macroscopic gas flow channel were researched. The results have shown that the longer the basic roof loading applies and the larger span, the greater the rock fractures develop; when roof weight- ing happens or is about to happen, the fracture development and connectivity of gas macroscopic flow channel are best, and the width of its horizontal fractures is three times wide as before roof weighting, which is the best time for gas drainage. Field application shows that the drainage efficiency increases by about 55% during roof weighting, and avoids gas exceeding its concentration limits.

关 键 词：瓦斯抽采 高位钻孔 宏观流动通道 裂隙 采空区 

分 类 号：TD712[矿业工程—矿井通风与安全]