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Using Smart Pits in Optimization

Updated October 19, 2017

This article applies to:
  • Softree Optimal

Softree Optimal can also decide which pit should be used if there is a choice.

  1. Open the Softree Optimal application.
  1. File | Open. Select Hart Rd optimal haul.dsnx. Press Open.
  2. Maximize the Profile window, ensure the Alignment Properties panel is visible.

At this point, Pit-1 is being used for all waste as there are no alternatives.

Figure 1: Waste pit usage at station 0.0 only.

  1. Add variable waste pits at stations 500 and 900:
    1. Make sure that V-align 1 is selected.
    2. Press the Options button and select the Pits tab.
    3. Press the Add button in the Pits dialogue box.
    4. Enter station 500 in the Pit Access Station dialogue box, press OK to accept and close.
    5. Make sure that Waste and Variable volume are set (figure below).
    6. Repeat to create another variable waste pit at station 900.

Figure 2: New waste pits added.

Notice that the Waste quality is Q1 (worst); this means that any material can be accepted by this pit. Capacity is set to inf (infinite); you can optionally limit the size of the pit by setting this property. Site preparation cost is set to zero by default.

    1. Press OK to close the options dialogue box.

Figure 3: Recalculate Range dialogue box with the Re-Cost option set.

    1. Set the Re-Cost^ check box when prompted with the Recalculate Range dialogue box.
    2. Press OK to recalculate and update the Optimal Haul.

Figure 4: Waste pit usage at stations 500 and 900.

Our new pits are both being used and Pit 1 at station 0 pit is not; this reduces the haul cost.

Now let’s add site preparation cost and see how the optimal haul calculation is impacted.

  1. Press the Options button. Select the Pits tab.
  2. Select Pit 4: waste variable, enter 10,000 as the site preparation $.
  3. Enter the same site preparation $ for Pit 1 and Pit 5.
  4. Press OK to accept the change as shown in the figure below:

Figure 5: Adding Site Preparation Cost

  1. When prompted to Recalculate Range, select OK.

Notice that the only waste pit being used now is the one at station 900; the optimal haul calculation has determined that, in this case, the extra hauling cost is less than the Site preparation cost of opening two pits.

Figure 6: Updated Opti-Haul Showing Pit Usage

  1. File | Exit. Do not save changes.