Numerical Simulation Research On Reasonable Borehole Spacing Of Presplitting Blasting In Coal Seam

The presplitting blasting in coal seam can effectively solve the problem of the difficulty of gas extraction in low permeable coal seam, and prevent and control the happening of gas disaster accidents. The determination of blasting borehole spacing can provide a reasonable test scheme for presplitting blasting in coal seam, to achieve the purpose of improving the permeability of coal seam therebyThe 3# coal seam of Lu'an mining area Zhangcun coal mine belongs to low permeability coal seam. With 2306 working face of this coal seam as the research object. The range affected of coal seam by presplitting blasting under the independent influence factors of explosive detonation velocity and control hole was studied by the method of numerical simulation, and so did the affected range of coal seam by different ways of blasting. Put forward the reasonable borehole spacing, and it was verified in the presplitting blasting experiment of this coal seam working face. The results indicated that the reasonable borehole spacing of presplitting blasting in coal seam under the influence of explosive detonation velocity was 4m; the range affected of presplitting blasting damage in coal seam with different detonation velocity explosive was basically identical; the reasonable borehole spacing of presplitting blasting in coal seam under the influence of control hole was less than 4m; the blasting damage effect of double blasting holes model was better than that of single blasting hole model. The reasonable borehole spacing of the two blasting holes by presplitting blasting with double blasting holes in coal seam was 8m; the field test results and the numerical simulation results are basically identical.