Offset to Face

Reporting the Distance of Blast Holes to a Face

The Offset to Face option reports on and displays information about the distance of blast holes to a face (as represented by a triangulation).

With the Offset to Face option, you can display and report the offset distance of a front row of blast holes to the blast face (specified by a triangulation). This is required by sites where blasting is a community issue. These sites often have to profile the face to be blasted and ensure blast holes do not come in a certain distance of this face. This would require the ability to move blast holes to match the tolerance required. Once the blast holes are drilled, the front holes are then surveyed down the hole and then displayed and reported again. This tool can be used by all drill and blast engineers against a face pickup to ensure optimal blasting.

Instructions

Load the blast layer and the triangulation(s) you want to use, then

Click the Offset to Face button on the Drill and Blast toolbar.

On the Drill and Blast menu, point to Analysis and Reporting, and then click Offset to Face to display the Offset to Face panel.

Enter the downhole interval of the offset in metres.

Enter the blast influence distance of the offset in metres.

Select the Generate report check box if you want to generate a report of the offset details. If you select this option:

Select Report all interval offsets or Report minimum offset only to indicate how to report the offsets.
Select or enter the name of the CSV file that will store the report information, or click Browse to select a file from another location.
Select the View in Excel check box if you want to view the report as a Microsoft Excel spreadsheet after it is generated.

Select the Highlight downhole intervals of close holes check box to highlight the intervals of downholes that are in a specified distance of each other. If you select this option:

Enter the minimum distance between holes in the Threshold distance box. Any holes that are closer than this minimum distance will be highlighted when you run the process.

Select a colour and line style to use for the highlight.

Select the Preview minimum offsets check box if you want to preview the minimum offsets.

Click OK.

Click on the triangulation you want to use. If you only have one triangulation loaded, you will be prompted to confirm that you want to use that triangulation.

Select the method of hole selection from the Select hole(s) menu. You can select by hole, by row, by echelon, or all holes.

Click on a hole in the group that you want to compare to the face.

If you selected Preview minimum offsets, you will be prompted to confirm that the preview is correct. You can rotate the triangulation to verify that the preview is correct, if desired. If the preview is correct, click Preview OK.

If you selected Highlight downhole intervals of close holes, you will be prompted to confirm whether or not you want to retain the highlighting. Click Retain highlighting of close holes to retain the highlighting or Remove to remove the highlighting.

The process then runs and the hole information is saved in the file you specified in the Report CSV file list. If you selected View in Excel, the information displays in an Excel spreadsheet, as well. The holes will be highlighted where they are in the tolerance of the face.