TUNNEL CONTOUR HOLE BLASTING METHOD USING DETONATING CODE

摘要

A tunnel back break reduction blasting method having an instantaneous nonelectric detonator and a detonating fuse is provided to reduce the back break corresponding to an electronic detonator and to obtain a flat blasting surface with excellent lag precision, and to protect the remaining bedrock of a tunnel effectively by blasting after blasting an outer auxiliary hole, thereby and applying destructive force toward a free surface only. A tunnel back break reduction blasting method having an instantaneous nonelectric detonator and a detonating fuse comprises the steps of perforating charge holes of a cut hole, a stopping hole, a bottom hole, a contour auxiliary hole and a contour hole formed on the front section of a tunnel according to the location, charging a detonator and an explosive to each charge hole, charging an instantaneous nonelectric detonator and an explosive to the outermost contour hole and connecting a non-electric detonator tube to a detonating fuse of 5g/m, and then connecting a non-electric detonator corresponding to the detonation lag of the outermost contour hole, and setting up the detonation time.