Extend collar points

You can use this function to change the length of individual blast holes, for example to make the toe of a blast hole extend to a bench level represented by a surface, or to crop the blast hole to that surface.

Prerequisites: For this function to be useful, at least one blast hole must be displayed in Graphics as a string.

To run this function: Choose Design > Blast design > Blast design > Extend collar points, or...

In the Function Chooser, type BLAST EXTEND SINGLE, and press ENTER.

Fields on the Bottom of hole parameters form

Field	Description
Toe position method	Set Length. Sets the length of the blast hole to Hole length. Set Elevation. Sets the elevation of the toe of the blast hole to an absolute elevation. DTM layer. Extends or reduces the length of the blast hole so that it stops at the surface in the layer you specify. DTM file. Extends or reduces the length of the blast hole so that it stops at the surface in the DTM file you specify. Set to Segment. Extends or reduces the length of the blast hole to a segment with which it intersects. You are prompted to select a segment that is open in Graphics. Selected Point. Extends or reduces the length of the blast hole to a point. You are prompted to select the point.
Hole length	The absolute hole length for the blast hole. This field is visible when you select the Set Length method.
Elevation	The absolute elevation of the bottom of the blast hole. This field is visible when you select the Set Elevation method.
Layer name	The layer that contains the surface that the toe of the blast hole will intersect. This field is visible when you select the DTM layer method.
Location	The name of the DTM file that holds the surface where the blast hole stops. This field is visible when you select the DTM file method.
ID	The ID of the DTM file that holds the surface where the blast hole stops. This field is visible when you select the DTM file method.
Object ID	The Object ID of the surface where the blast hole finishes. This field is visible when you select the DTM layer or DTM file method.
Trisolation ID	The Trisolation ID of the surface where the blast hole finishes. This field is visible when you select the DTM layer or DTM file method.
Make Visible?	Determines whether the lower DTM is displayed in Graphics.
Segment offset	The distance from the segment to offset the blast hole.
Fix value	If you specify a Segment offset, either the offset distance or the bearing must be slightly different from the value you specified. Bearing. The bearing of the blast hole is as you specified, and the offset distance is slightly different from the offset you specified. Offset. The offset distance of the blast hole is as you specified, and the bearing is slightly different from the bearing you specified.
Subdrill distance	The amount of additional length to add to the blast hole to account for subdrill.
Hole bearing	The angle of orientation of the blast hole in plan view. A Hole bearing of 0 is north.
Hole dip	The angle of orientation of the blast hole in section view. A Hole dip of 0 is directly into the ground.
Hole diameter	The diameter of the blast hole. Hole diameter is a property of each point in the blast hole.

Output

The holes you selected are extended or reduced to the length you specified.

The following image shows an example where Toe position method is set to DTM file.