Application of Small-bore Long-short Hole Blasting in Roof Pre-splitting of Large Mining Height Face

To reduce the strata behavior of Changping Mine 4311 large mining height face when first weighting comes, according to hard roof condition of 4311 large mining height face, we propose pre-splitting blasting scheme of large mining height face and use small-bore long-blasting hole blasting technique as an innovative method. It proves that the blasting effect is good, and first weighting pace of main roof is reduced from 45 m to 30 m, which ensures safety and efficient mining of thick coal seam in Changping Mine.