NOVEL PRESPLITTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a presplitting method allowing a reduction of an excess crushing range around the bottom of a borehole and improving the effect of cutting a rock mass. SOLUTION: The presplitting method comprises filling granular explosives having a specific gravityρof 0.50-0.70 into the bottom of the borehole. A space room is provided in the upper part of the filled explosives. COPYRIGHT: (C)2004,JPO