Study On Wave Mining And Comprehensive Water Control Technology In Fully Mechanized Caving Face With Large Water Inflow

In the mining process of deep water mine face,due to the large water content of the roof of the coal seam,after the face is opened,a water-conducting fissure zone is formed above the coal seam,leading to the overlying aquifer,allowing the water body in the aquifer to flow into the working face and this will affect the normal safe mining of the working face.Especially in the working face arranged along the roadway,a large amount of water inrush will cause a certain degree of damage and destruction on the small coal pillars,affecting its bearing stability.Therefore,it is necessary to take corresponding measures to comprehensively control the roof water during mining of the working face to ensure the mining safety of the working face,the stability of the small coal pillars in the section and the smooth discharge of the roof water.The thesis takes the deep strong water-filled working face of Gaojiapu Coal Mine in Shaanxi as the research background and aiming at the problems of safe mining of mining face and drainage of mining face in mine which have a large amount of water,researches have been carried out on the laws of overlying rock movement,wavy mining plan and parameters of working face,special drainage roadway and drainage hole layout.Finally,obtained a series of safe mining technology of wave mining in the fully mechanized caving face of the big water mine.Through the monitoring analysis of the face pressure of the working face,the movement law of overburden rock during the mining of the fully mechanized caving face is obtained.On this basis,the wave mining plan is proposed,that is,the wave mining is adopted during the mining of the working face,which is artificially manufacture the Watershed behind the face.According to the roof movement law and the undercover volume of the coal mining face during the mining of 101 working face,The best distance of wave mining is 16m.(the wave crest is 8m and the wave trough is 8m).We need to ensure that the height difference between wave crest and wave trough is not less than 0.8m,and the average degree of up and down mining in each step is 6.5°(The maximum undercover volume of the shearer is 370 millimeter,each knife is raised or 100 millimeter undercover in the actual pushing process).At the same time,according to the actual situation of the working face,a number of comprehensive water prevention and control technical measures such as water retaining wall behind the face,cleaning and diversion were implemented.Aiming at the problem of difficult drainage when the working face passes through the syncline structure,a mine-specific drainage roadway was designed.The numerical simulation method was used to analyze the degree of the influence of mining face mining at different locations on the spillway is analyzed.That is,after the working face is fully excavated,the bottom plate destruction depth is 13 meter.Combined with the test results of the surrounding rock loosening circle of the roadway,when designing the location of the spillway,the surrounding rock loosening circle of the roadway shall be considered according to the maximum value of 2.43 meter.That is,the special drainage roadway should be excavated outside the range of 16 meter below the floor of the working face.At the same time,for the problem that the mine water is difficult to drain after the working face is pushed through the drain roadway,a special drain hole is designed and determine the structure and parameters of the hole.The successful application of wave mining and comprehensive water prevention and control technology in fully mechanized caving face is of great practical significance for the high-yield,high-efficiency and water hazard prevention of similar large-water mines.