Determine The Protection Scope And Inspect The Protection Effect Of Protective Seam Mining Of The Wang Xingzhuang Coal Mine

With the increase of mining depth, high gas and coal and gas outburst mine gradually increased, and mining protective seam is the most valid and economical regional prevention measures. The key problem encountered in extracting protective seam mining is to determine the protected scope and effect. This paper take the Wang xingzhuang coal protective seam mining as the research background, Research about the protected scope and effect of protective seam mining, the main contents include:Through survey and investigate protected seam parameters of the Wang xingzhuang coal to determine the scope of the upper protective seam mining. Through arrange drill hole of visiting gas flow in the protected seam, obtain results of a secondary pressure relief process of the protected seam and showing a M-type distribution of gas flow along with the upper protective seam promote forward,On this basis, defined the relief angle along mine direction. through measurement and analysis the range of coal-bed gas content of different scale, defined the relief angle along the direction of face arranged. FLAC^3D software is applied to simulate distribution of face abutment pressure with excavation size changes, determined the law of protected seam normal deformation,based on the protection rule of normal deformation of protected seam, determine the scope of the upper protective seam mining, through comparison, the result of the numerical simulation was close to the field investigation.Through site visits, obtain results of variation of relevant parameters of the Wang Xingzhuang coal's relieving seam. Coal-bed gas pressure of protected seam by the 0.45MPa down to the 0.14 MPa, coal-bed gas content by the 11.6 m³/t down to the 4.87 m³/t, the out-flow of gas of face 11051 in protected seam reduction, about 50% of that has been poured into the face of protective seam, the coal seam permeability coefficient by the 0.02 m²/ MPa²Â·d increased to 30.48 m²/ MPa²Â·d, than the original coal seam permeability coefficient increased by 1429 times, The forecasts target of prevention of coal and gas outburst are basically fall to the marginal value below after the protective seam mining. These show that, in the protective seam mining, great changes have taken place on relevant parameters of protected seam, get a lot of gas release, eliminated the outburst risk of relieving area of protected seam.