Blast hole crest tolerance
You can use this function to identify which blast holes are within a specified distance of a pit wall or the edge of a bench. When a blast hole is too close to the pit wall, the blast can cause unwanted fragmentation of the pit wall. When a blast hole is too close to the edge of a bench, the blast can cause rock to be blown a great distance from the source of the blast, possibly causing damage to equipment, existing ramps, or people.
Prerequisites: At least one blast hole is displayed as a string. A segment that marks the boundary of a physical feature (such as a crest or toe of a bench) is displayed.
To run this function: Choose Design > Blast design > Blast design > Blast hole crest tolerance, or
Fields on the Blast crest tolerance form
| Field | Description |
|---|---|
| Tolerance | The minimum distance from each blast hole, to the boundary segment, that you require for a safe blast. |
You are prompted to select a crest segment.
Output
Circles are displayed in Graphics around each blast hole for which the distance to the crest segment is less than or equal to the Tolerance.
Note: If you select a segment that represents the crest of a pit wall, BLAST CREST TOLERANCE checks the distance from the blast hole to that segment only. If the toe of the pit wall is closer to the blast hole than the crest, when you run this function you should select the segment that represents the toe of the pit wall .
