Dozer Push

This command calculates the volume and distance moved for a dozer push from a highwall into a pit. The program also draws closed polylines that represent the cut and fill areas and the path of the dozer. Dozer Push works with a cross-section view of the pit. Before running this routine, you need a polyline that defines the existing ground including the top surface, highwall and pit bottom. A second polyline is optional for the Cut Bench to push along and also optional is one for the bench bottom. The Cut Bench polyline could be the top of coal for example.

The Dozer Push command starts with the dialog box shown here:

 

• Horizontal Scale and Vertical Scale: These are the scale factors for the drawing to generate text, symbols, and vertical exaggeration, among other things.
  
• Cut Push Percent: Push Percent is the percent grade the dozer cuts down from the surface. Enter as a percent.
  
• Pit Push Percent: The Pit Push Percent is the percent grade that it will push out into the pit before spilling over to the repose angle. Enter as a percent, positive or negative.
  
• Repose Angle: Repose Angle is the angle that gravity pulls down the fill slope, as it spills over the edge. Enter as an angle.
  
• Wedge Angle: Wedge Angle is angle the dozer will cut down when the Use Wedge Angle option is on. Enter as an angle
  
• Spoil Percent: Spoil Percent is the percent grade of the spoil pile as the dozer pushes uphill. Enter as a percent (up). When there is not enough room in the pit to fit the cut at the pit push percent, the remainder will get placed by building up a spoil pile at this specified Spoil Percent. The program will prompt for a base point to start building the spoil slope. This point is typically at the top of the coal so that the spoil pile will not overlap the coal and create extra rehandle.

• Cut Swell Factor: The Cut  Swell Factor is multiplied by the cut to determine the amount of fill. Enter as 1.2 for 20 percent swell.
• Layer: This layer is used for the entities created by this routine including the new surface polyline and labels.
  
• Use Wedge Angle: With the Wedge Angle option, the cut will begin by starting at the top of pit and moving down at the Wedge Angle for the specified Cut Width. It will continue down at the wedge angle for the specified horizontal width. The Cut Push Percent is not used if the Wedge Angle is used.
  
• Sequence Number: This is the sequence step number that is added to the SEQ sequence file for Process Dragline Sequence.
  
• Direction to Push: The dozer must be specified to push to the right or to the left.
  
• Define Cut Depth By: The Polyline Method will prompt to select the Cut Bench Polyline. The polyline method can use either a closed or open polyline. For a closed polyline, the cut area is defined by the polyline. For the open polyline, the polyline represents the surface that the dozer will cut down to. The dozer cut will be located by finding the top of the pit and then moving back along the top surface for the Cut Width entered below. The top of the pit is identified by finding the first grade that is greater than or equal to the Push Percent grade. Then the dozer will cut down at the Push Percent until it reaches the bench polyline. The Pick Points method will prompt for the lower left point and the lower right point. The line drawn between them is then set to the cut surface. This controls the cut width, so the value entered below for Cut Width will not be used.
  
• Output Step to Sequence File: Turn this option on to add the step to a new or existing SEQ file. This file is processed with Process Dragline Sequence.
  
• Store Step to Report File: This option will create or append a CUT file that is processed with the command Dragline Section Report.
  
• Find Cut/Fill Balance: The Find Cut/Fill Balance is a special option that finds the offset distance where the cut and fill balance and draws the push polyline. With this option, the bench polyline is not used.
• Report Average Push: When there are several different push distances and slopes, this option will average them to report the overall push distance and slope.
  
• Cut Width: When using the Polyline method to Define the Cut Depth, this is the total width of the push, from the Cut Push distance down to the Cut Polyline, then across the Cut Polyline the remaining distance to get to the entered width. 
• Update Existing Polylines: This option will replace the existing ground polyline with the updated ground polyline.
  

• Label Style: Sets the style for the text entities.
• Text Size Scaler: This scaler is multiplied by the Horizontal Scale to set the size of the text entities.
• Area Decimals: Sets the precision for the end areas.
• Cut/Fill/Rehandle Labels: Sets the names for these values.
  
• Label Push Distances: This option will label the distance from the centroid of the cut block to the edge of the highwall where the repose angle.
• Draw Centroids: Draws the specified symbol at the centroids for the cut and place areas.
  

This command does one push at a time. To perform multiple cuts, run Dozer Push for each one. For every push, a cut area and fill area are drawn as closed polylines. The ground polyline and bench polyline are also updated to represent the modified surface. The centroids of the cut and fill areas are used to calculate the push distances. During a stage of the dozer push, there might be rehandle where some of the cut area includes previous fill areas. There is an option to deal with rehandle by selecting the closed fill area polylines that were drawn in a previous Dozer Push. The amount of rehandle is reported and the swell factor is not applied to the cut in rehandle. When there is not enough room to drop the push into the pit, the fill needs to be pushed up to a spoil pile. The program automatically detects this case and prompts for the bottom bench polyline for the spoil start. The end of this polyline is where the spoil grade begins.

Shown next are some dozer push examples with the important points labeled.

Prompts

This command handles many stages of the dozer push. Which values to use from the dialog and the prompting depend on the stage of the dozer push.

Select existing grade polyline:
Pick lower Left cut point:
Pick lower Right cut point:
Select fill areas to rehandle (Enter for None).
Select objects:
CUT (bsf): 9182.6 REHANDLE (bsf): 0.0 FILL (lsf): 9182.6
PUSH: 141.4,3.6%
Pick Point for Label (Enter for none):
Select existing grade polyline: pick the ground polyline
Select cut bench polyline: pick the bench polyline
Select fill areas to rehandle (Enter for none)
Select objects: press Enter
Cut: 308.7 Fill 308.7
Pick Point for Label (Enter for none): pick a point
Select existing grade polyline: pick the ground polyline
Select cut bench polyline: pick the bench polyline
Select fill areas to rehandle (Enter for none)
Select objects: pick the rehandle polyline
Select objects: press Enter
Pick Point for Label (Enter for none): pick a point
Select existing grade polyline: pick the ground polyline
Select cut bench polyline: pick the bench polyline
Select fill areas to rehandle (Enter for none)
Select objects: pick the rehandle polylines
Select objects: press Enter
Select bottom bench polyline for spoil start: pick the bottom bench polyline
Pick Point for Label (Enter for none): pick a point

Pulldown Menu Location: Surface
Keyboard Command: dozer
Prerequisite: Surface and strata polylines