Study On Stress Distribution Law Of Pre-mining Upper Layered Concave And Convex Coal Body And Optimization Of Mining Roadway Position

In this paper,based on the research background of "concave and convex" coal body formed by stratified strip mining in Jinqiao Coal Mine,through theoretical research and numerical simulation,the stress distribution law of this kind of "concave and convex"coal body and the failure depth of plastic zone are grasped.It provides the basis for the next optimization of the position of 1308 track along the groove,and then determines the best position of the track along the groove in the first fully mechanized top coal caving face(1308 working face).At the end of mining in 1308 working face,in order to arrange adjacent working face(1310 working face),the reasonable width of section coal pillar is determined by numerical analysis.Finally,through the mine pressure monitoring of 1308 working face,the rationality of the position of 1308 track along the groove is verified.The main research contents and achievements of this paper are as follows:(1)Through UDEC numerical simulation software,according to the specific mining situation of Jinqiao Coal Mine,the mining of 1308top and 1310top working faces is simulated.the simulation shows that the stress distribution of the floor presents a "double camel peak",and the peak stress decreases gradually with the increase of the depth of the floor.The failure depth of plastic zone caused by coal seam floor is basically consistent with the theoretical calculation.(2)When determining the track alignment of 1308 working face,12 different roadway layout schemes are simulated.The stress distribution in the coal pillar,the deformation of the roadway surface and the plastic zone around the roadway are analyzed and compared.the width of the coal pillar is 36 m,the range of the plastic zone is only 1 m,and the deformation of the roadway is the smallest.Therefore,the best position of 1308 track along the groove is located in the middle of the coal pillar between the working face on 1308 and the working face on 1310.(3)After mining in 1308 working face,12 schemes with different pillar widths are designed,and the internal stress,roadway deformation and plasticity of coal pillar are analyzed.the width of section coal pillar is 7 m,and the coal pillar has strong supporting capacity.The stress distribution in the coal pillar presents a "double camel peak",the deformation of the roadway is the reduced gradient inflection point,and the width of the coal pillar in the section is finally determined to be 7 m.(4)Through the monitoring of advance supporting pressure,lateral supporting pressure and roadway deformation in 1308 working face,it is shown that the deformation of roadway is small,the layout of roadway is reasonable,and the safe and efficient mining of coal mine is realized.