Study on extraction parameters of high-yield and high-efficiencyworking face roof strike high borehole

The output of a coal mine in Shanxi province is large, resulting in a large amount of absolute gas emission from the working face.The gas problem in the upper corner of the working face has become the main factor restricting the safe and efficient production of the mine.Therefore, aiming at the existing problems of gas control in the upper corner of the mine, the design and optimization of extraction parameters for high-level boreholes along the roof of the goaf are carried out.Through theoretical calculation and numerical simulation, the strata of the end hole of roof borehole are obtained, and the formula for calculating the number of boreholes is deduced.The field test of extraction effect is carried out at 3103 working face of the mine, and the parameters suitable for the layout of high-level boreholes in the mine are obtained to ensure the safe and efficient production of the mine.