METHOD FOR DRILL-BLAST BREAKAGE OF ROCKS AT PENETRATION OF MINE WORKINGS

摘要

Method for drill-blast breakage of rocks at penetration of mine workings in breakage cycles includes drilling of blast holes near the base of the working with placement in rows of trench holes, central and contour breakage holes placed symmetrically with respect to the vertical axis of the working, with charging the holes with explosive substance and with sequential explosion first of cutter, then trench holes with following short-delay firing of the rows of breakage holes. The rows of breakage holes and the upper row of the trench holes are placed in arc that is turned with its convexity to the side of the base of the working, the breakage holes of the first penetration cycle in each row are drilled with decrease of length of those in direction to the ceiling of the working, central breakage holes in each row are under-charged with decrease of the under-charging value in direction of contour breakage holes.