The invention discloses a method for hard roof advanced precracking control caving in a
coal mine stope, and belongs to the technical field of
coal mining, and particularly relates to a hard roof advanced precracking control caving method for determining parameters of borehole
layout, such as, the pore opening positions, the depth of drilling holes, the angle of the drilling holes and numbers of the drilling holes of hard roof advanced precracking drilling in the
coal mine stope and calculating the explosive
payload of the drilling holes. According to the characteristics of hard roof fracture,five blast holes in a fan shape are formed to form a
fixed angle; the middle portion and the end of the a working face which are most difficult to break of the hard roof can be effectively pre-cracked, so that the roof can collapse as required; based on the characteristics of blasting, the blasting sequence of the blast holes from the middle portion of a
cutting hole to both ends can maximize thefree surface of the blasting and reduce the explosive
payload, and the operation is convenient; and a calculation formula of the explosive
payload of the hard roof of preceding loosening blasting indeep hole is given quantitatively to enable the control of hard roof to be more scientific, quantitative, accurate and simple.