Study On 3D Electrical Detection Of Roof And Floor Of Group A Coal Face In Gubei Mine

Roof and floor water damage is one of the main factors threatening the safe mining of coal seam.In order to ensure the safe mining of coal seam,it is necessary to find out the water rich area of roof and floor accurately.At present,the three-dimensional electrical method of coal seam working face is based on the coal seam with relatively high resistivity,which repels the current,and can generalize the detection results into half space detection.The reliability of the detection results is an issue of concern.In this paper,through theoretical analysis,numerical simulation,physical simulation and engineering application,the three-dimensional electrical detection of roof and floor of group a coal working face in Gubei mine is systematically studied.The results show that when the engineering site is a half space field,the position of the abnormal body can be delineated effectively by 3D electrical detectionThe results show that:(1)if there is a low resistivity anomaly in the roof(floor),the resistivity will be slightly reduced in the bottom(roof)detection results,and the pseudo bottom resistance area may be formed;(2)if there is a high resistance abnormal body in the roof(floor),the detection result of the floor(roof)will be improved;(3)even if the roof(floor)has abnormal body,the floor(roof)can detect the location of low resistance abnormal body.The detection results of group a coal working face in Gubei Coal Mine:(1)the water rich area of roof and floor can be effectively delineated by using three-dimensional electrical method;(2)in the three-dimensional electrical exploration,although the roof(floor)low resistance anomaly has an impact on the floor(roof)detection,it is usually slightly increased the resistance value of the abnormal body at the bottom(roof),and the electrical response characteristics of the abnormal body with low resistance will not be greatly changed(3)when the distribution range of the abnormal body of the roof(floor)is large enough to cause the change of the electric field distribution in a large range,and the abnormal body of the floor(roof)is small or no abnormal body is not enough to cause the large change of the electric field distribution in the range,the phenomenon of the interaction between the roof and the floor can be produced.(4)When the three-dimensional electrical method is used to detect the roof and floor of working face,although it is in the whole space field in theory,the detection results are less affected by the interaction of roof and floor abnormal bodies.Therefore,in order to improve the efficiency of data analysis,the detection results can be generalized as half space detection.Figure 66 Table 30 Reference 50...