Study On Water Drainage Technology Of No.2 Coal Roof Aquifer Area In No.11 Mining Area Of Maiduoshan Coal Mine

The casualties caused by water disasters in coal mines account for a large proportion of casualties in coal mines in China.Therefore,in order to protect coal mine from water disaster,it is of great significance to study water prevention and control.In this paper,taking No.2 coal roof in No.11 mining area of Maiduoshan Coal Mine as the research object,the drainage and drainage technology of No.2 coal roof aquifer in No.11 mining area was studied by means of theoretical analysis,numerical simulation and field engineering practice,and the regional drainage and drainage scheme was formulated,and the following results were obtained:Based on the analysis of the hydrogeological drilling and pumping test data of Maiduoshan Coal Mine,the dynamic change of water level in the long observation hole and the sparseness of the lower aquifer of Zhiluo Formation on the roof of No.2coal mining face in adjacent Hongliu Coal Mine,it is concluded that the lower aquifer of No.2 coal roof in No.11 mining area of Maiduoshan Coal Mine is sparseness.Based on the construction principle of local variable weight model,the local variable weight water abundance index model of each spatial point is established,and the local variable weight water abundance index is drawn by isoline,and the water abundance zoning map based on local variable weight is obtained.The water abundance zoning of the lower aquifer of Zhiluo Formation in No.2 coal roof of No.11 mining area is carried out.Generally speaking,the water abundance in the northeast and southwest of the mining area is strong,while that in the northwest and southeast is weak.Based on the actual roof and floor conditions of No.2 coal face in No.11 mining area,theoretical analysis and numerical simulation were used to predict the development height of water-conducting fissure zone and caving zone in No.2 coal face in No.11 mining area.The caving zone height of No.2 coal face in No.11 mining area predicted the height of water-conducting fissure zone with reference to surrounding mines,and the split-mining ratio of thick coal seam and medium-thick coal seam was 11.85 and 16.22 respectively.Through numerical simulation,it can be seen that when the mining height of No.2 coal is 3.87 m,the maximum development height of the water-conducting fracture zone is 31.3m,and the split-mining ratio is20.59.The water-conducting fracture zone produced by the mining of No.2 coal face can communicate with the aquifer of Yan ’an Formation and the lower aquifer of Zhiluo Formation between No.1 and No.2 coal faces.According to the evaluation results and water gushing prediction results of the roof aquifer of No.2 coal face in No.11 mining area,the comprehensive analysis results of aquifer water abundance zoning and the prediction value of the development height of "two zones" in the working face,the scheme of water drainage and drainage in the lower aquifer of No.2 coal face in No.11 mining area was studied,and the technical scheme of water drainage and drainage in the roof during mining in No.2coal face in No.11 mining area was formulated,which ensured the safe mining of the mine.This paper has 33 figures,25 tables and 57 references.