Single Decoupled Blasthole Tests and the Significance of the Results to Presplitting and Boulder Busting


The position of a major joint in relation to a blasthole has a significant effect in presplitting. A series of model tests was conducted in specially prepared 12 x 9 x 6 inches concrete blocks each with a 3/8 inch blasthole, loaded with 15-grain detonating cord. To simulate a semi-infinite burden similar to field pre-split conditions, the blocks were lightly constrained. Additional experiments were conducted without constraints to ascertain the resulting fracture pattern in boulder blasting mode. If the blasthole is relatively near to the free face, the angle of crater is greater. Further, at a distance approximately five times the diameter of the blasthole, the cratering ceases. A recurring split appeared all the way back to the abutted end of the blocks far in excess what is expected in presplitting. By conducting an extensive investigation, an application in presplitting and boulder busting for this phenomenon is found.

Meeting Name

12th Annual Symposium on Explosives and Blasting Research


Mining Engineering

Document Type

Article - Conference proceedings

Document Version


File Type





© 1996 International Society of Explosives Engineers (ISEE), All rights reserved.

Publication Date

01 Jan 1996

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