Development And Application Of Water-conducting Fracture Zone In Jiangjiahe Coal Mine

Roof water inrush is one of the water hazards in coal mines.Under the influence of working face mining,the aquifer water in the stope caving zone will pour into the stope in a short time through the water-conducting fracture zone,resulting in a downhole flood.Threats to underground safety production.The overlying stratum of No.4 coal seam in Jiangjiahe Coal Mine has multiple aquifers,and the roof water inflow increases significantly during the mining process of the working face in the second mining area.Therefore,it is necessary to study the development law of the water,conducting fracture zone of the overlying stratum during mining.In this paper,theoretical analysis,field test and numerical simulation methods are used to conduct in-depth research on the development law of the water-conducting fracture zone in the ZF213 working face of the No.4 coal seam in Jiangjiahe Coal Mine.The results are as follows:(1)The distribution range of "two zones" of ZF 1410 working face was simulated and analyzed,and the simulation results and the measured results confirmed each other,indicating that the rock parameters and mechanical boundary conditions of the numerical model were set reasonably,which is a good way to predict the "two zones" of the overlying rock of ZF213 working face by numerical simulation method.Band "range provides a credible basis.(2)The bearing load of overburden,the breaking distance of overburden,the position of key layers,and the relationship between key layers of overburden and aquifers in ZF213 working face were analyzed by theoretical methods;(3)The "two zones" distribution of the ZF213 working face was simulated and analyzed.The results show that the height of the fracture zone is 150m from the upper part of the coal seam.It is estimated that there are 4 adjacent aquifers overlying it,including the sandstone pore-fracture aquifer of the Lower Cretaceous Luohe Formation,The water from the conglomerate fissure aquifer of the Lower Cretaceous Yijun Formation,the sandstone fissure aquifer of the Middle Jurassic Zhiluo Formation,the coal seam of the Middle Jurassic Yan’an Formation and its roof sandstone aquifer may enter through the water-conducting fissure zone work surface.(4)Numerical simulation analysis obtained the distribution range of the"two zones" of the overlying rock under the conditions of 4 different coal seam thicknesses in the ZF213 working face;the analysis obtained the "two zones" of the overlying rock under the conditions of 8 different working face lengths of the ZF213 working face." distribution law,and considering its impact on the aquifer,the results show that the reasonable length of the ZF213 working face should be 100-120m.(5)The transient electromagnetic method was used to find out the relative water-rich anomaly area above the roof of the ZF213 working face.(6)According to the above research results,targeted measures are put forward for the water control of the ZF213 working face of Jiangjiahe Coal Mine and the working face under similar conditions.