Method for setting blasting employing bar-like charge

摘要

This invention is to provide a setting method of blasting in bar-like charge which is reasonable to achieve both of safety and maximum blasting or fracturing efficiency, and to provide the method which can be setting accurately a charge hole diameter d relative to the other facters. PPA safety charge amount L is derived by controlling a nominal total fracture rock volume V, namely, a filler length P.sup.2 . times.a charge hole length M, with an inclination coefficient sin.sup.3 . alpha.×a blasting coefficient c.PPA charge hole diameter d is derived by the fact that the (sin.sup.3 &agr;·c. multidot.P.sup.2 ·M) is equal to a ((&pgr;/4)d.sup.2 (M-P)) which applies the expression for deriving a volume of a circular column.