Journal Published Online: 08 June 2018
Volume 47, Issue 2

The Rock-Breaking Mechanism of Directional Fracture Blast Using an Irregular Shape Cartridge and Its Field Application



The testing system of digital laser dynamic caustics was performed here to examine the super-dynamic fracture mechanics of directional blasting crack, which, using an irregular shape cartridge, revealed the rock breaking mechanism of directional fracture blast. The findings show that the blasting primary crack fracture features—the typical tensile break, the variation trend of the dynamic stress intensity factor (DSIF), crack propagation velocity, and crack length— were more or less the same, the primary crack fracture was finished during 60–200 μs, the limit DSIF scarcely exceeded 1.5 MN/m3/2, and the arrest toughness of the blasting fracture was about 0.3 MN/m3/2. The irregular shape cartridge showed significant detonation wave unloading effects and detonation gas jet effects in the accumulative direction or slotting direction; the “air wedge effect” of the high-pressure detonation gas jet acted as the main drive for further expansion of the compression radial crack in the accumulative direction (or slotting direction), which also held the propagation of the compression radial crack in the nonaccumulative or nonslotting direction). Additionally, the accumulative cartridge and slotted cartridge were applied to the construction field, and it was found that the directional fracture blast was enabled, the good blasting fracture surface was formed, and better economic benefits and less operation time could be achieved using these two cartridges.

Author Information

Wang, Yanbing
State Key Laboratory for Geomechanics and Deep Underground Engineering, Beijing, China
Pages: 18
Price: $25.00
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Stock #: JTE20160496
ISSN: 0090-3973
DOI: 10.1520/JTE20160496