Create Pit Design

1. On the Open Pit menu, point to Automated Pit Designer, and then click Create Pit Design to display theCreate Design panel.

   

2. Select a Specification file (*.pds.spec) from the drop-down showing the current working directory, or enter a new name. Alternatively, click the button to browse to the required file’s location.

   All the parameters you set up in the design process will be stored in this specification file. Once it is saved, you will be able to reopen your design work to make edits or continue where you left off. The specification file will be stored in your current working directory.

3. Select the required Design Type. Choose between Pit and Dump. This determines how certain parameters will be utilised such as Rock/Void Access for a ramp.

4. Select the required Projection Direction. Choose Upwards to project up and out, or Downwards to project down and in.

   Note

   When the pit designer is constructing a design it will either progress upwards through the benches from the lowest elevation to the highest elevation, or downwards in the opposite direction. The process that the designer uses depends not only on the design direction, but also on the design type.
   

   A pit going upwards corresponds to the design getting larger because the earlier strings will be contained within the later strings. This is analogous to a dump going downwards. This case of the design is called out.

   The opposite case is either a pit going downwards or a dump going upwards, in which the later strings are contained within the earlier strings. This case is called in.

   Design Type	Projection Direction	Design Case
   Pit	Upwards	Out Projects upward, increasing in circumference.
   Pit	Downwards	In Projects downward, decreasing in circumference.
   Dump	Upwards	In Projects upward, decreasing in circumference.
   Dump	Downwards	Out Projects downward, increasing in circumference.

5. Under Default Slope Parameters, set the default Batter angle and Berm width for the design. These two parameters are mandatory and are used when no advanced parameters are supplied, or as a defaults when the advanced parameters do not cover a region.

6. (Optional) Select Contour existing block model to automatically create seed strings based on information from an existing block model. This works especially well if you have a block model containing results from the pit optimiser or a variable populated with pit numbers.

7. Click Next to open the Define Blocks panel.

1. From the Block Model drop-down, select a block model file. Alternatively, click Browse... to located the required file.

   You can then select the variable you want to base your contour on by entering the pit information, or by using the standard block selection criteria.

2. If you select Use pit variable, enter the following details:

   • Pit numbers: Select the variable that contains all of the pit numbers from the drop-down list.

   • Pit number: Enter the number of the pit that you want to base your contouring on.

3. If you select Use block selection configure the following options:

   • Mask by variable

     Select the Mask by variable checkbox to restrict the blocks by a block model variable. You will need to select the variable and value to mask by from the Variable and Value drop-down lists.

     Example:  To restrict blocks to those where Material equals Ore, select Material as the variable and Ore as the value. The block model variable may be numeric, such as the grade variable Au or character, such as Geology variables.

   • Use test condition

     Select the Use test condition checkbox to use a further constraint upon a numeric block model variable and enter the condition in the Condition field. The maximum size of the condition is 132 alphanumeric characters.

     Refer to the appendix, Operators and Functions, for a full list of available operators and functions.

     Example:  To select only blocks that have an iron value greater than 10.0, you would select the Use condition checkbox and enter Fe GT 10.0 in the Conditions field.

   • Use bounding triangulation

     Select the Use bounding triangulation checkbox to restrict the blocks by a triangulation. Select the bounding triangulation to use from the Triangulation drop-down list, or click Browse... to select a triangulation from a location other than your working directory.

     Note:  This option is not applicable to open or 2D triangulations.

   • Use bounding surfaces

     Select the Use bounding surfaces checkbox to restrict the blocks by bounding surfaces. Select triangulations from the Upper triangulation and Lower triangulation drop-down lists, or click Browse... to select triangulations from a location other than your working directory.

   • Use bounding box

     Select the Use bounding box checkbox to restrict the blocks by a box. Choose either Use model coordinates or Use world coordinates, then enter the minimum and maximum X, Y, and Z coordinates as opposite vertices of the bounding box.

     Note:  If the block model origin is set at 0,0,0, then select Use world coordinates for the minimum and maximum X, Y, and Z coordinates. If the block model origin is set at real world coordinates, then enter coordinates for the bounding box that are offset a certain distance from the origin.  The distance of offset will be determined by the dimensions of your bounding box. It will be the distance to the minimum and the distance to the maximum X, Y and Z from the origin of the block model.

4. Click Next to open the Define Benches panel.

Bench Generation

If you selected the selected the Contour existing block model option, the minimum and maximum bench elevations will automatically be calculated. You will just need to enter the Bench height, which defines the height of a single bench.

If you did not selected the Contour existing block model option, you will need to specify the Min elevation, Max elevation, and Bench height. You can edit these settings later, but the pit designer needs at least two benches to work with.

Tip:  It is a good idea to round these numbers since the exact elevations from the block model will be used to populate these fields. The pit designer can easily handle any numbers you choose, however, future reports based on the resulting design may be easier to deal with. For example, in the image below the initial elevations were from 523.4 to 628.7, but were rounded to 520.0 and 630.0 respectively.

After the elevation and bench height information has been entered:

• Click Generate to populate the Benches table automatically.

• Click Clear if you need to delete all entries in the table.

• Click Next to open the Process Contours panel.

On the Process Contours panel, set the following parameters by dragging their sliders:

• Close holes: The results from the pit optimiser will leave behind certain areas that it does not consider worth mining. These holes are represented by dashed lines. By zooming in you will be able to see them, if they exist. Using the Close holes slider control, you can adjust the sensitivity that determines which blocks will be included in the final pit design. As you increase the setting, more blocks will be included.

  

• Round corners and Smoothness: Use these controls to remove blocks by smoothing the contours.

• Flatness: The Smoothness control smooths the line by adding splines, which can dramatically increase the number of points in a line. Use the Flatness control to filter out some of the points.

  

When you are satisfied with the results, click Next.

Select the contour lines you want to import into the pit designer to become seed strings. Click on a string to select it, and a preliminary pit design will be created. If you make a mistake or wish to select a different line, simply click on the string again to deselect it.

You can add as many lines as you want, but it is recommended that you only add a couple.

Right-click to confirm your choice to import the contour lines as seed strings.

Selecting Yes will bring in the selected contours as seed strings and display the Pit Designer toolbar menu with different editing functions.