Study On Reasonable Reserved Coal Pillar Width For Gob-Side Entry Driving By Roof Cutting And Pressure Relief In Selian No.2 Mine

With the development of the times,human demand for electronic intelligence industry is increasing,which indirectly leads to more and more power consumption.Although China is vigorously developing new energy industries such as solar energy and wind energy,China's main power supply and demand is still obtained from non renewable coal resources.Therefore,safe and efficient mining of coal mines is bound to become a development trend in the future.Because the superposition of multiple stope stresses has caused some interference to the surrounding rock stability of goaf side roadway,many experts have proposed the roof cutting and pressure relief technology to transfer the additional load of overlying strata to goaf through artificially reserving cutting joints,so as to reduce the influence of mining lateral support bearing force and dynamic pressure of 12407 working face on goaf side roadway of 12406 working face,Improve the stress of coal pillar and roadway roof to a great extent,and create conditions for reasonably reducing the reserved coal pillar width.On the basis of roof cutting,this paper systematically analyzes the lateral bearing pressure of the working face,the vertical stress distribution of coal pillar and roadway roof,and the deformation of surrounding rock along the goaf after roof cutting and pressure relief,reasonably selects the coal pillar size of the belt trough in 12406 working face,and realizes the maximization of resource utilization on the premise of ensuring the safe and stable excavation of the belt trough in 12406 working face.The whole framework of the paper is divided into the following aspects:(1)Belt along the trough in 12407 from the coal,rock sample processing,grinding,and carries on the uniaxial compression test,triaxial test,the Brazilian splitting test,measured its compressive strength,elastic modulus,poisson's ratio,cohesive force,internal friction Angle,the basic mechanical parameters such as tensile strength,its coefficient calculation,understand the strong degree of surrounding rock,provides the basis for the stability of the roadway surrounding rock control.(2)The mechanical model before and after roof cutting is established and analyzed qualitatively.The pressure relief effect of blasting roof cutting is analyzed by simulating the stress distribution of coal pillar before and after roof cutting and the displacement between roadway roof and floor and two sides.The drilling design is carried out according to the roof rock distribution of the working face,and the field blasting test is carried out with reference to the crack development of blasting hole,Determine the best blasting parameters.(3)ABAQUS software is used to simulate the stress and deformation distribution of coal pillar and roadway roof when different coal pillar widths are reserved for roof cutting and pressure relief.The influence of 12406 mining face on the deformation of 12406 belt trough is predicted and analyzed,and a reasonable support scheme is put forward according to the deformation of surrounding rock of goaf roadway.(4)Through the on-site monitoring of the lateral support pressure produced by the roof cutting section and the non roof cutting section during the mining of 12407 working face,the variation law of the lateral support pressure before and after the roof cutting is analyzed,the best reserved coal pillar width after the roof cutting is determined,and the influence range of the pressure step during the mining of 12407 working face and the mining advance of the working face is monitored,Compared with the ground pressure monitoring data of the non roof cutting face,the roof cutting effect is verified.This paper systematically analyzes the changes of stress and displacement of surrounding rock before and after roof cutting,verifies the blasting effect of roof cutting parameters,determines the optimal width of reserved coal pillar,improves the coal recovery rate on the basis of ensuring safe mining,provides reference for coordinated control technology of roof cutting and pressure relief of surrounding rock and reasonable reservation of coal pillar width,and provides basis for roadway layout along the goaf.Figure[67]table[21]reference[82]...