Water Safety Safety Performance Evaluation Of 9102 Fully Mechanized Caving Face Before Mining

The main coal seam of Changheng Coal Mine is 9.2m.Fully-mechanized caving mining is adopted.The coal seam is covered with water from the goaf of 4 coals,roof sandstone fissure water,and strong Ordovician aquifer underneath.Water inrush has occurred during the early mining process of the mine.,Flooded lane accident.The 9102working face has a strike length of 1687m,with well-developed faults and hidden geological anomalies,and a large amount of water hazard prevention and control works.In order to ensure green and efficient mining of the 9102 fully mechanized caving face and avoid the recurrence of water inrush accidents,pre-mining water safety evaluation was carried out.It is very necessary.On the basis of consulting the cutting-edge technology and latest research results of disaster management for strong confined aquifers,faults,collapse columns,and geological anomalies at home and abroad,this thesis analyzes the possible water source of mining face,and aims at geophysical abnormal areas,fault fracture zones,The concealed geological anomaly body is designed with up and down exploration grouting control and inspection verification holes.According to the"Three Under"Coal Mining Code,"Coal Mine Water Control Rules"and other regulations,the floor damage depth and Ordovician water inrush are calculated.Coefficients,predicted the development height of roof mining caving zone and water-conducting fissure,evaluated the anti-deformation ability and water resistance of the floor rock mass;built a mathematical analysis model to reveal geological anomalies such as fault fracture zones,collapsed columns,and geological anomalies Possibility of activating water conduction under the influence of mining.Obtained the following results:(1)The length of the machine lane in the 9102 working face is about 1684m,the length of the air lane is about 1680m,the width of the cutout is about 200m,and the mining thickness is 9.2m.The water hazards affecting the safe mining of this surface are:the overlying 4103 fully mechanized mining face and the south wing 9101 fully mechanized caving face accumulated water in the goaf,F1 fault water,XI geological anomaly body and water from the Ordovician strong aquifer of the floor.(2)Various geophysical exploration methods such as radio wave penetration,audio electric perspective and transient electromagnetic were used to detect and analyze the 9102working face,and 34 geological anomaly areas were found,including 13 water-rich anomaly areas on the floor.In the abnormal area,135 downhole exploration holes were designed,with a engineering volume of 13568.6m,and a total of 4247.9 tons of cement was injected;it has been verified that the abnormal geological bodies(including)such as faults and collapse columns in the working face have poor water conductivity,and the final grouting of each hole The hole pressure and the water output of the inspection verification hole are both less than 1m~3/h,which meets the design requirements.(3)The main rock formations of the floor and roof of the working face are sandstone and silty mudstone.The test results of mechanical properties show that its strength is low and the content of water-resistant minerals is high.Most of them belong to soft rock to medium hard.The sandstone layers in the sandstone are all interbedded with siltstone and argillaceous sandstone.According to the characteristics of the rocks in contact with Ordovician limestone,they are all aluminum mudstones.The thickness is not less than9.5m.The water blocking performance is excellent.Safe and green mining of the surface has a good blocking effect.(4)Rock samples were taken,physical and mechanical properties were tested,actual geological conditions were digitized through software,combined with experimental data to quantify model parameters,and a computer analysis model of mining evolution law was established,which affected faults and geological abnormalities in the mining industry.,The height of the water-conducting fissure zone of the top plate and the depth of the failure zone of the bottom plate are obtained.(5)Based on the analysis results,design underground water drilling holes for the 4th coal goaf and floor limestone grouting reinforcement and reconstruction holes;drain the water in the 4th coal and 9th coal gobs of the south wing to increase the floor water barrier The effective thickness is calculated to have a minimum value of 0.030Mpa/m and a maximum value of 0.045Mpa/m,which is less than 0.06 Mpa/m.It meets the requirements of the"Detailed Rules for Water Prevention and Control in Coal Mines"and meets the conditions for safe mining.(6)The paper uses the"big well method"and the"hydrogeological analogy method"to estimate the water inflow at the working face,evaluate the water inflow under normal working conditions and under extreme conditions of the working face,and obtain the normal and maximum water inflow.Water inflow.According to the relevant results and the"Details of Coal Mine Water Prevention and Control",the coal mine’s drainage system was optimized and designed,combined with the actual characteristics of the 9102 working face,to formulate relevant emergency response plans.To sum up:From the perspective of water hazard prevention and safe mining,with the safety monitoring and drainage work in place during mining,there is no hidden safety hazard in mining work at the working face.As of the completion of the thesis,the first 1086m of the working face has been mined,the water inflow is less than 15m~3/h,and no water hazard safety accident has occurred.It shows that the research results of the thesis have high reliability,and the methods and methods adopted for geophysical prospecting prediction,drilling verification,advanced drainage of goaf water,fault fracture zone and collapse column grouting transformation and treatment are practical and feasible,and have a wide range of popularization and application.value.Figer[36]table[28]refrence[68]...