Research And Application Of Separated Strata Grouting Mining Technology Of Zhaozhuang No.2 Coal Mine

Since entering the 21st century,various ten-million-ton-level mines have been continuously constructed and put into operation,and recovery speed is increasing in geometric multiples;meanwhile,hidden dangers and accidents such as highway subgrade subsidence,road damage,building cracking,house collapse and groundwater level down caused by coal mining have occurred from time to time.At present,the more serious problem faced by major coal mining enterprises is how to scientifically,safely and effectively solve a series of potential safety hazards caused by surface subsidence caused by coal mining.Based on this problem,taking Zhaozhuang No.2 Coal Mine of Jinneng Holding Coal Industry Group as the industrial background,the methods of theoretical analysis,drilling for core and on-site measurement and tracking are used to conduct research on the separated strata grouting mining project on the 2309 and 2307 working faces of Zhaozhuang No.2Coal Mine.Firstly,an on-site survey is conducted find out the lithology and hydrogeological conditions of the roof and floor and the characteristics of coal seams of the Zhaozhuang No.2 Coal Mine,and the mining conditions of the 2309 and 2307 working faces are systematically analyzed.Secondly,methods such as theoretical calculation and drilling for core probing are used to carry out the mining design of separated strata grouting on the 2309 and2307 working faces,the key layer for grouting is determined,the construction location of the grouting hole is determined according to the actual conditions of 2309 and 2307 working faces,and the key data such as the pressure value of the grouting hole orifice is determined through calculation.Thirdly,the mine pressure law in the grouting and filling mining area of the 2309 working face is studied and compared with the original mine pressure behavior data,and then the mine pressure behavior law of this area is summarized,thus providing a basis for the future roof management of the mine.Finally,the ground subsidence and deformation of 2309 working face is observed and compared with the settlement data of 1304 working face,it is concluded that the filling mining has achieved a significant subsidence reduction effect.