The Study And Application Of Control Technology Of Hard Roof In The Deep Mining Thin Coal Seam

The 15445 working face of Jiulong coal,a subordination of Fengfeng Group,is a thin seam hard roof mining working face.This working face has difficulties in managing the roof and complex conditions in coal mining.And it is the focus on the study of the coal in our country at present.Therefore,the study of the mining pressure principle of the thin seam can provide effective technical support for the safe and efficient production.The main coal seam of Jiulong coal mine is the coal seam 2,and the thickness is about 5.85 m and has better occurrence conditions,but it has high gas content,so for the safe and efficient recovery,we make the coal seam 4 as the protective layer to mine.Using the method of theoretical analysis,the method of similar simulation and the method of numerical simulation to analysis and research on the control technology of the tight roof in the deep working face.And the technology of prevention and control is constructed that is suitable for the hard roof of the deep thin seam.Firstly,through the method of theoretical analysis,the 15445 working face as the protective layer can be done.At the same time,the mine pressure of the overburden can be analyzed.Secondly,through the method similar simulation,the regularity of mine pressure of overburden stratum and the strata movement of 15445 working face can be studied.And we can also know the characteristics of the overlying strata subsidence deformation and the characteristics of rock breakage through the experiment.Thirdly,using the numerical simulation method of FLAC3 D to establish the numerical model of the 15445 working surface,and study the distribution range and the concentration of stress in mining process.The purpose of this paper is to analyze the variation of the stress concentration area and the numerical value of the overlying strata in mining process.Finally,according to the characteristics of the difficult caving in the hard roof of 15445 working face,the project team uses the presplitting blasting to make the hard roof more fragmented and weakened.This process can make the security improved.In order to mine the coal seam 2 that can have a better protection effect.