Dragline Spoil

Generate spoil pile sections

The Dragline Spoil option to create profiles (along the length of the pit) and spoil pile sections that would be produced by a dragline mining the strip. A typical pit and spoil section is shown below.

In order to generate the spoil sections, a set of workings and two surface triangulations are required.

• Workings
  The workings consist of a set of cross section lines generated through either the Create Sections or Insert Sections options. For spoil sections, the sections must go from the spoil side to the highwall side of the plan. In the following diagram, the existing spoil area is on the left and the pit is on the right, so the section lines must be designed going from left to right.
  

  Diagram 2 - Workings

• Triangulations
  The first surface or new design surface is the surface triangulation for the pit to be mined, consisting of the new highwall and roof of coal. The second surface, or the existing surface model, is the old surface. The second surface is made up of the existing pit high wall, the floor of coal previously mined and the existing spoil pile. The existing spoil can be a designed surface, a survey of the spoil pile or a previously designed spoil surface.
  

  Diagram 3 - Second Surface

Note:  The file name extension for the triangulations must be ' .00t '.

Instructions

• Select Open Pit menu
• Select Pit Volumes submenu
• Select Dragline Spoil option

Select an existing surface triangulation. The following panel is then displayed.

Spoilpile panel

Toe offset width/Safety bench width/Safety bench slope

Safety bench slope along pit

This field is currently not used by the system.

Low wall angle

Enter the low wall angle. This value must be greater than or equal to the angle of repose.

Angle of repose/Swell Factor

Maximum dragline height

Enter the height of the spoil above the dragline working level.

Dragline working height

Enter the dragline working height.

Select OK.

You will then be prompted to select the toe of the coal face in the existing pit. The toe of spoil offset is with reference to this string.

If the spoil is generated where there is no string, then the toe of the spoil will be offset from the top of the pit section. Also, when there is no toe of coal, there must be sufficient space on the existing surface to accommodate the pit.

Once the string is selected, you will be asked to confirm your selection. Once confirmed, the spoil and pit sections are then generated.