This article is a workflow on how to design a haul road for a mine in the Virtual Surveyor app. We'll create the structure of a haul road with a properly drawn centerline, slope angles, and create the grading for the road, then estimate material volumes, export the surface as a machine control model, and track the build progress over time.


Overview


Setup a Baseline

We'll want to create a baseline Timestep as the starting point and foundation of the project that includes the elevation model (the DSM) and the orthophoto from the initial survey.


To setup a baseline, we'll want to show the Timeline using the button from the View tab or status bar and change the name of the first Timestep to 'Baseline'. 

Set up a baseline Timestep in the Timeline for a haul road design.


Create a Haul Road Design Timestep

Next, we'll need a new Timestep that includes a copy of the initial DSM and orthophoto that we can modify or alter as we design the haul road:

  1. Click on Add Timestep
  2. Type in the Timestep name for the haul road: Haul Road Design.
  3. Copy the DSM and Orthophoto from the Baseline.
  4. Switch to the Haul Road Design Timestep.
  5. Paste the DSM and Orthophoto into the new Timestep.

Create a haul road design Timestep in the Timeline.


Design the Structure of the Haul Road

As we design the structure of the haul road, it is essential to get the centerline, road curvature, slope angles, and road measurements accurate.  


Draw the Centerline for the Haul Road.

To start the haul road design, switch to 2D mode and we'll select the Polyline tool and start drawing the centerline at the base of where we want the haul road to start. It might be good to make the vertices equidistant for consistency, so we'll enable the Distance Drawing Guide and set it to 5 meters. With the Distance guide enabled:

  1. Draw the centerline up to where the slope begins
  2. Switch the Line Drawing Mode to Arc and draw the arc to the top of the slope and left click to create the arc. 
  3. Switch the drawing mode back to Free and continue drawing the line up to the next slope.

Draw the design line up a slope using the polyline and the Arc for the Line Drawing Mode, along with the Distance Drawing Guide.


Repeat the same process and draw another arc line up the next slope ending it on the next flattest part of the slope, making adjustments where necessary. If we draw the line too close to the next slope and it becomes difficult to draw an arc that matches where the centerline needs to go, just go back a few vertices by pressing the Backspace key.

Finish the design line for the haul road switching between the Free and Arc Line Drawing Modes.


Give the Center Line a Gradual Slope.

We'll need to adjust the slope in two sections for this haul road in order to give the line a gradual slope that is safe for trucks to drive on. For the first section on the lower part of the road we'll right-click on the centerline to select it and bring up the mini toolbar. 

  1. Select Edit Vertex
  2. Change the mode to Interpolate Z (Curve), which allows us to create a gradual slope along the road. 
    1. Select a vertex that starts a few vertices before the line begins going up the slope, as the starting point.
    2. Then select a vertex a few vertices after the slope has levelled out.
    3. Doing this will help ensure the slope is gradual without any abrupt elevation changes.

Interpolate the vertices of the design line up the slope using Interpolate Z on a Curve to create a gradual slope without abrupt elevation changes.


Again, repeat creating a gradual slope on the second section using Edit Vertex and Interpolate Z with a curve. Use the same concept of picking a few vertices before and after the slope begins and ends in order to make the slope as gradual as possible.

Again, interpolate the slope gradually on the upper part of the design line using Interpolate Z on a curve.


Create the Road Edges and Slope Angle.

Next, we'll create the width of the road so large trucks can drive safely on the haul road and also add slope angles to account for water runoff. To do this:

  1. Right click on the centerline to select it and choose Offset Line. 
  2. Change the method to Slope and the slope angle to -1 degree. 
  3. Activate the Distance drawing guide and set it to 4 meters. 
  4. Offset the first part of the centerline out to the 4-meter marker using left click. 
  5. Then select the centerline again and create an offset of the centerline on other side.

Create offset lines from the haul road design line to make the edges of the road with a -1 degree slope from the center to the outer offset lines for water runoff.


Now we'll add a berm at the edge of the road towards the cliffside; to help with safety of the vehicles along the cliff's edge (we've enabled the Transparent lens to help show all the drawn lines). To add the berm: 

  1. Select the outer line and activate the Offset Line tool.
  2. Change the slope to 45 degrees
  3. Change the Distance guide to .25 meters.
  4. Add an offset line at the .25 meters guideline.
  5. Change the Z Offset Method to ΔZ and keep it set to 0 meters
  6. Also keep the Distance guide to .25 meters, then click the guideline again to create the top portion of the berm. 

Create the berm of the haul road using the Offset Line tool.


Triangulate the haul road breaklines.

And for the last part of designing the structure, select all of the drawn road lines holding Shift with left click-and-drag, and use the Triangulate Selection tool to create a surface for of the road.

Triangulate the haul road design using the design line and it's offset lines.


Create the Grading for the Haul Road

Now we will need to connect the structural design with the surrounding using slope that assure the stability of the haul road. We use the Grade tool for this:

  1. Ensure the haul road surface design is selected
  2. Navigate to the Tools tab. 
  3. Change the Cut Slope to 60 degrees and the Fill Slope to -60 degrees.
  4. Click on the Grade button.

Create the grading for the haul road using the created haul road surface design.


Once the calculation is complete, we see a nice model of the road built into the hillside. 

View the model of the haul road built into the hillside of the quarry.


Inspect the Design

The design looks like it worked out really well with the measurements that were used. Using the Timeline, we can get another perspective of the haul road design to ensure it can be properly built and check to see if any areas of the haul road design need to be improved.


For a quick up-close look:

  1. Select the haul road design line.
  2. Navigate to the Tools tab.
  3. Click the To Profile button. 
    1. This will open the Profile View

Inspect the model of the haul road by converting the design line to a Profile Line.


As shown, we have created a nice gradual slope up the hill and again at the top of the hill that we were able to create using the Interpolate Z option. The blue line reflects the original topography.

View of the haul road design comparing the original slope with the design line.


Profile section lines. We can create some section profiles to help visualize the haul road in sections. The section profiles allow us to see details for the portions of the terrain that will be cut and filled. We can inspect the -1 degree slope on either side of the central haul road design line, as well as the protection berm we created using offset lines.


To see the section profiles:

  1. Select the profile line.
  2. Navigate to the Tools tab. 
  3. For this example, we'll set the Across measurement to 15 m.
  4. Click Section Profiles.
    1. The section profiles are created in their own layer. 

Create profile section lines for a perpendicular look at the haul road.


We can go through each section profile to see the consistent slope angle of the haul road along with the cut fill levels. 

Cycle through the section profile lines and see each section of the haul road design at every 15 m.


Material Estimation

Now we can use the design to estimate how much dirt we'll need to build the structure. We can use the Cut/Fill tool to estimate the material quantity. We'll hide all lines so that only the design surface is shown:

  1. Select the design surface.
  2. Use the Extract Boundary tool to create a boundary around the modified terrain.
  3. Select the extracted boundary.
  4. In the Tools tab, change the Volumes dropdown option to Use a Timestep.
  5. Select the Haul Road Design Reference State from the Timeline options.
  6. Click the Cut/Fill tool to generate the material estimation.

Estimate how much material needs to be cut away and filled to build the haul road.

A look at the cut and fill map of the haul road design.


Cut/Fill Information. With the Cut/Fill selected, we can see how much dirt we'll need to remove and how much we'll need to add with the total volume displayed in the Selection Box.

The Cut and Fill details of the graded haul road design, including the Net Cut of material.


Export the Machine Model

We can export a machine model so that the haul road design can be built on-site via excavator.

  1. Ensure the completed design surface is enabled and showing in the Viewport.
    1. Also ensure that no other design lines are showing.
  2. Go to the Export tab and set the file Format to .xml.
  3. Click Export Survey and name the file. 
  4. Click OK to export the design to a chosen file location.

Export the machine model of the haul road.


Monitor the Build Progress of the Haul Road

Once the haul road is being built, we can fly and add the next drone dataset as another Timestep to compare and track progress for the build. 


Use the Terrain Creator app to create a new timestep for the next stage of the haul road: 

  1. After processing photogrammetry in the Terrain Creator app, click the To Existing button. 
  2. The dataset is moved to the Virtual Surveyor app as a newly created Timestep.
  3. The timestep is automatically created in the Timeline and is generated with the drone flight date as the Timestep name.


As Built. When construction for the haul road is complete, we can capture one last drone survey and do a final check between the design and the as-built haul road to affirm that the work is complete.