金家渠煤矿工作面顶板富水性分析及疏放水对策

Drainage countermeasures and watery analysis by geophysical exploration for the roof of first-mining face of Jinjiaqu coal mine

金家渠煤矿110301工作面水文地质条件复杂,顶板富水性强,严重影响工作面安全回采。为准确分析工作面顶板富水性区域,采用瞬变电磁探测技术探明工作面横向范围与纵向顶板上方80 m范围岩层富水性,圈定了富水异常区段及等级。对工作面范围内钻场、钻孔数量、钻孔深度、角度等参数优化,确定工作面切眼300 m附近钻场间距100 m,设计2个钻场共计5个钻孔,其他区域钻场间距200 m,每个钻场布置2~4个钻孔,每个钻场设置一个平行于巷道的钻孔,一个垂直于巷道的钻孔,另外的两个钻孔与巷道成60°夹角,钻孔倾角15°~55°。通过涌水量观测累计疏放水36.2万m^3,单孔最大涌水量154 m^3/h,半衰期约20天;后稳定在76 m^3/h,有效降低顶板含水层涌水量、水位与水压,保证工作面安全回采。

The hydrogeological conditions of NO. 110301 working face in Jinjiaqu coal mine are complex and the roof of mining face is rich in water,which has bad effects on the safety of mining on the working face. In order to acquire the accurate area of the watery region of roof on the working face,the transient electromagnetic detection technique is used to detect the water enrichment of rock strata in the range of 80 m above the transverse and longitudinal roof of the working face,and the section and grade of the abnormal water-rich strata are delineated. According to the optimization of drilling field,drilling number,drilling depth,angle and other parameters in the working face,2 drilling fields distributing 2-4 boreholes and being 200 m apart are designed nearby the cutting hole of working surface,and 2 drilling fields distributing 5 boreholes and being 100 m apart are designed nearby the others. Each drill field is equipped with a hole parallel to the roadway and a hole perpendicular to the roadway. The other two boreholes are at an angle of 60°to the roadway. The borehole inclination angle is 15°to 55°. The accumulative drainage is 362,000 m3 through the observation of water inflow,and the maximum water inflow of a single hole is 154 m3/h. Half life is about 20 days; The latter is stabilized at 76 m3/h,which can effectively reduce the water inflow,water level and water pressure of the roof aquifer and ensure the safe mining of the working face.