CONTOUR DEEP-HOLE CHARGE

FIELD: blasting operations for production of preset mining extraction contours without a considerable dislocation of the rock mass continuity beyond the rated profile, applicable in mining industry and construction. ^ SUBSTANCE: the contour deep-hole charge includes formation of a string of elements 1 of explosive 2 and initiation. The string is formed from the deep-hole bottom in single polymeric branch 3 in the form of cylindrical elements 1 of explosives 2 of a similar height and diameter formed by pinch 4 of branch 3 and being spaced at distance ld=le(rhoedech 2/rhoechddh 2-l) cm, where le - the length of the cylindrical element of the string of the contour explosive charge, cm; dech - the diameter of the cylindrical element of the string of the contour explosive charge, cm; ddh - the deep-hole diameter, cm; rhoe - the explosive density, g/cu. cm; rhoech - the density of deep-hole loading by explosive, q/cu. cm. Initiation is effected by detonating cord 8 fastened with one end on the lower end face of last cylindrical element 1 in the bottom section of the explosive passing along the charge column in the form of alternating linear sections 9 between explosive cylindrical elements 1 and binder assemblies 10 of each explosive cylindrical element 1 in diameter. ^ EFFECT: enhanced efficiency of contour blasting due to simplified method for formation of the contour charge, expanded assortment of the explosive, reduced cost. ^ 7 cl, 1 dwg