Research Article
Analysis and Application on Controlling Thick Hard Roof Caving with Deep-Hole Position Presplitting Blasting
Table 8
Technical parameters of presplitting blast holes.
| Parameters | Unit | Primary blast presplitting | Periodic blast presplitting | Auxiliary blasting | A1 | B1 | A2 | B2 | A3 | B3 | C1 | D1 | C2 | D2 | C3 | D3 | E1 | E2 |
| Length | m | 39.2 | 38.7 | 34.5 | 39.2 | 38.9 | 35.1 | 15.7 | 15.8 | Horizontal angle | ° | 0 | 0 | 3 | 7 | 0 | 0 | Elevation angle | ° | 23 | 16 | 31 | 24 | 39 | 32 | 23 | 16 | 31 | 24 | 39 | 32 | 90 | 81 | Sealing length | m | 13.2 | 13.2 | 11.5 | 13.2 | 13.4 | 11.6 | 5.2 | 5.3 | Cement slug/Stemming | m | 3.2/10.0 | 3.2/10.0 | 3.0/8.5 | 3.2/10.0 | 3.5/9.5 | 2.7/9.0 | 1.2/4.0 | 1.3/4.0 | Charge length | m | 26.0 | 25.5 | 23.0 | 26.0 | 25.5 | 23.5 | 10.5 | 10.5 | Charge weight | kg | 31.2 | 30.6 | 27.6 | 31.2 | 30.6 | 28.2 | 12.6 | 12.6 |
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Tips: the single cartridge length is 0.5 m and the charge weight is 0.6 kg.
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