基于圆内接多边形的优化揭煤钻孔布置方式研究

In-polygon borehole layout for rock cross-cut uncovering

为了解决煤矿瓦斯抽采过程中,利用"三花眼"布孔方式缩短抽采钻孔间距,有效消除了瓦斯空白带,同时带来的钻孔数量增加和部分区域重复抽采问题。通过理论计算,提出了圆内接多边形的设计方案,并优选出了最佳实施方案。同时结合石门揭煤实例进行优化,结果表明,利用圆内接六边形进行钻孔优化布置(即当有效抽采半径为R时,沿煤层走向施工抽采钻孔间距为31/2R,沿煤层倾向施工抽采钻孔间距为1.5R),比传统设计防突钻孔的工程量减少了3792m,降低率为23%,具有重要的理论意义和实用价值。

In order to solve the problem of gas extraction in coal mines,the"delta mode"layout method is used to shorten the interval between drainage holes,which eliminates the blank zone of the gas,while leading to increased number of boreholes and repeated extraction in some areas. Through theoretical calculation,the in-polygon borehole design schemes are proposed and selected,and then optimized combining with the rock cross-cut uncovering example. The results show that compared with the traditional design of outburst prevention drilling,the drilling construction decreases by 23%( 3792 m) using the in-hexagon optimized borehole arrangement,that is when the effective extraction radius is R,the drilling spacing along the coal seam strike is 31/2R,and that along the dip is 1. 5 R. The results have important theoretical significance and practical value.