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Aiming at the actual problems such as bad effect of gas drainage, slow mining speed, high cost and so forth of drilling along layers in mining face of coal seam of low air-permeability but high gas-content, effect of orifice pre-splitting blasting on crack extending in coal seam was studied through adopting ANSYS/LS-DYNA software. Different diameters and depths of holes were set in the simulation,...
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