Top-cutting And Gob-side Entry Retaining Technology For Transporting Flat Roadway In 10902 Working Face Of Jingu Mine

In order to solve the problem that the roof of No.9+10 coal mine is hard in lithology and difficult to collapse by itself,this paper takes 10902 haulage drift of jingu mine as the research object,adopts theoretical analysis,numerical simulation,industrial practice and other methods to carry out the research on roof cutting and pressure relief gob-side entry retaining technology,deeply discusses the feasibility and applicability of this technology in jingu mine,and finally achieves good gob-side entry retaining effect,and draws the following conclusions:(1)Through laboratory tests of rock physical and mechanical properties,key index values such as compressive strength,compressive strength,shear strength,elastic modulus,Poisson's ratio and RQD of roof and floor of 9+10 coal seam are obtained,and the stress-strain relationship of rock samples under tensile and compressive shear is analyzed,which provides basis for numerical simulation and selection of strengthening support parameters.(2)By analyzing the stress distribution law of the working face stope,the stress distribution model of the surrounding rock after blasting roof cutting is established,and the rotary sinking process of the key blocks of the basic roof and the movement law of the overlying strata are clarified.It is concluded that the roadway support after roof cutting is less difficult and the overall economic cost is low,and it is necessary to carry out presplitting blasting roof cutting on the hard roof.(3)According to the geological conditions of Jingu Mine,FLAC3 D is used to numerically simulate the distribution law of the lateral support stress of solid coal and the displacement of surrounding rock of roadway under the cutting height(0m,4m,8m,12m)and cutting angle(5°,10°,15°,20°).Finally,the cutting height of 8m and the cutting angle of 15 are determined to be the optimal solutions for cutting and relieving pressure.(4)According to the actual needs,the reinforcement and auxiliary support scheme for 10902 transportation roadway is designed.The reinforcement anchor cable is proposed to carry out secondary support for the roof,and the combined support of single-I-steel-composite iron shoe is proposed to carry out auxiliary support for the side of the roadway.The rationality of the selected parameters is verified by monitoring schemes such as the surface displacement of surrounding rock of the roadway,stress monitoring of single pillar and peeping at blasting holes,etc.The deformation of the roadway is small,and Jingu Mine can produce safely and efficiently.There are 62 figures,4 tables and 73 references in this paper.