地面钻孔并行三维电法探测煤矿灰岩导水通道

DETECTION OF LIMESTONE WATER-CONDUCTING CHANNELS IN COAL MINE BY PARALLEL 3D ELECTRIC METHOD OF SURFACE BOREHOLES

提出利用地面钻孔并行三维电法探测煤矿灰岩导水通道,为煤矿灰岩水害防治提供新的物探手段。该方法在地面需布置3个钻孔,在各孔中置入一条电极电缆,电法测线需控制探测目标地层。将3钻孔电极电缆连成统一观测系统,利用并行电法仪采集AM法数据。将孔中各电极统一编辑坐标,对AM法数据进行三维电阻率层析成像,可得到3钻孔间三维电阻率变化情况。根据富水区与正常岩层间的电性差异情况,分析富水区可能的电阻率表现形式,再结合已有钻孔地层柱状、巷道涌水以及注浆资料等,得到灰岩地层中含水区及导水通道范围。将此方法应用于淮南矿业谢桥矿的探测,结果表明:该方法较准确地查明突水区灰岩地层导水通道,能很好地指导灰岩段注浆堵水工作,使得东风井车场涌水量大大减小,消除灰岩突水威胁。

It is put forward that the parallel 3D electrical method of surface boreholes can be used to detect the limestone water-conducting channels;and it is also a new geophysical prospecting means for the prevention of limestone water disaster in coal mine. Generally,three boreholes are set on the ground and an electrode cable is imbedded in each borehole to detect the objective strata. After the observation system of the parallel electric method is correctly connected,the AM mode of data-collecting is adopted by this method. Coordinate of each electrode in borehole is edited;and electrical resistivity tomography of AM data is conducted to obtain the 3D resistivity changes among the three boreholes. Based on the electrical property differences between water-rich area and normal strata,the possible resistivity manifestation of water-rich area is analyzed. Combining with the existing data such as stratigraphic column,water gushing in roadways,grouting materials,etc.,the distribution ranges of aquifer region and water-conducting channel are found out. The exploration case for detecting water-conducting channels in Xieqiao coal mine of Huainan mining industry by using this method is conducted. The detection results show that this method can be used to well find out the limestone water-conducting channels in water inrush area. It provides a good guidance to the work of grouting and water plugging in limestone strata,which leads to dimish the water inflow of Dongfeng well yard greatly and the threat of limestone water inrush have been well removed.