| Autor: |
Aubertin, J. D., Hutchinson, D. J., Diederichs, M. S. |
| Předmět: |
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| Zdroj: |
Blasting & Fragmentation; Feb2021, Vol. 13 Issue 2, p77-101, 25p |
| Abstrakt: |
Salt blasting involves significant differences when compared with hard rock blasting, due to the distinct geomechanical properties. Rock salt is characterized by moderately high stiffness (20 - 40 GPa) and very low resistance in tension (~1 MPa). Energy losses near the blasthole in rock salt are at least an order of magnitude higher than in typical hard rocks, which limits the amount of available energy necessary for cratering. Salt blasting practices therefore typically favor low VOD explosives characterized by a less efficient detonation reaction, which lead to a cratering mechanism that is less driven by radial fractures originating from the blasthole, and more defined by the interaction between emitted and reflected pressure waves. Consequently, traditional (hard rock) blast design methods cannot properly capture salt response to blasting. The present work proposes practical guidelines to define site-specific blast design characteristics for rock salt deposits. The design methodology involves using single hole blast (SHB) tests to quantify the main characteristics associated with the cratering mechanism, and their influence on blasthole diameter to burden (S - B) and spacing to burden (f -B) relationships. Experimental work performed at three salt mines is presented to illustrate the proposed methodology. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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