中国矿山工程

In order to avoid the safety problems caused by the large area collapse of the overlying rock in the goaf during the mining period of the fully mechanized working face with hard roof, taking 1501 fully mechanized working face as engineering background, based on the analysis of No.5 coal seam roof strata，combined with the practical application, the paper puts forward the technology of weakening hard roof by deep hole blasting. After field application, the first weighting step of the roof is shortened to 19.5m, and there will be no large area hanging in the goaf, which creates good conditions for the production of the working face.