Table 3 Drilling parameters.
From: Study on parameter optimization of deep hole cumulative blasting in low permeability coal seams
Drilling number | Type | Aperture | Drilling depth | Charging length | Sealed hole length |
|---|---|---|---|---|---|
#1 | Extraction hole | 94 | 80 | – | – |
#2 | Blasting hole | 89 | 45 | 20 | 12 |
#3 | Extraction hole | 94 | 80 | – | – |
#4 | Blasting hole | 89 | 45 | 20 | 12 |
#5 | Extraction hole | 94 | 80 | – | – |
Unit | – | mm | m | m | m |
