| China is rich in coal resources,which has the characteristics of good economic utilization and strong guarantee.Coal resources,accounting for 56.8%of the national energy structure,is an vital source of national energy development and has played an important role in the instant and steady development of the domestic economy.However,the hydrogeological conditions of coal mining areas in China are complicated,and it is difficult to mine coal because of many factors.In particular,as the complexity of the water-filling conditions of mineral deposits has increased with the increase of mining depth in recent years,the degrees of difficulty of mining has enhanced,resulting in the frequent occurrence of various accidents in the mine,which seriously affects the safe production of the mine.Gubei Coal Mine is located in Fengtai County,Huainan City,Anhui Province.There are 8 mineable coal seams,and the main coal seams are 13-1,11-2,8,6-2,1 coal;The South No.1 mining area is the first mining area of the 1st coal seam,and the 13321 working face is the second working face after the 13121 working face in the South No.1 mining area;In the process of working face mining,the aquifer of C3I group is the direct aquifer of floor with an average thickness of 32.6m.The distance of 1 coal seam between the bottom plate and the aquifer roof is 16.5?21.0m,and the water head pressure is 5.2?5.9MPa,exceeding the safe mining water pressure value,mining is threatened by limestone water of Taiyuan Formation.In addition,in the presence of a vertical water-conducting structure,the deep Ordovician aquifer may have a hydraulic connection with the Taihui aquifer.which indirectly threatens coal mining.In order to avoid the occurrence of water inrush accidents and ensure the safe mining of coal mines,Gubei Coal Mine carried out water hazard control projects for the 13321 working face.Based on the support of the mining area data,this paper evaluates the effect of the working face water hazard control project,mainly analyzing the basic situation of the study area and the work of 13321,such as geological and hydrogeological conditions,etc;Using the AHP decision-making method,a mathematical model is established for the exploration and treatment project of limestone water damage from the perspective of drilling quality,grouting quality,and comparison of water pressure,water quality,water temperature,and water volume before and after grouting reinforcement,the final grouting effect value V=0.202,governance effect of limestone water disasters showed good.In order to ensure the safe mining of the coal seam,the FLAC3D software is used to compare the floor damage depth before and after the grouting treatment of the working face floor from the perspective of numerical simulation.The results show that after grouting reinforcement,the hydraulic connection between the fault and the aquifer becomes weaker,and the risk of water inrush from the floor in the goaf is relatively small.At the same time,the water hazard safety of the mining floor limestone in the 13321 working face is evaluated from the calculation of the limestone water inrush coefficient of the working face floor and the prediction of the water inflow of the working face.Figure[32]table[26]reference[73]... |
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