VirtualSurveyor provides dedicated tools to calculate stockpiles accurately and consistently. This article walks you through a common set of different stockpile types that you might run into and explains how you can measure them correctly with the VirtualSurveyor app.
By understanding how boundaries, reference surfaces, and terrain modeling work together, you’ll be able to create dependable stockpile calculations with confidence — no matter the site conditions. You'll see how to validate your work visually, generate clear PDF reports, and export results as CSV or GIS files for further analysis.
Overview
- Remove Conveyors
- Stockpile Baseline Boundary
- Stockpile Surface Type
- Create a Stockpile
- Validation
- Tips and Tricks
Remove Conveyors
Before calculating a stockpile, it’s important to remove any objects that hang over or sit on top of the pile. Equipment such as conveyors, wheel loaders, or other machinery should not be included in the volume calculation.
Start by removing conveyors and other unwanted objects from the surface model using the Replace Terrain tool.
For more complex terrain cleaning workflows, refer to the Remove a Conveyor article, which covers advanced removal techniques in greater detail.
Stockpile Baseline Boundary
Every stockpile calculation begins with a boundary that defines the footprint of the pile. Use the Boundary tool to draw a line around the stockpile area. Drawing boundaries is often easiest in 2D view mode, where edges and overlaps are easier to identify.
First draw the boundary around your stockpile, then follow the Create a Stockpile section in this article to see how to use that boundary to define the correct surface and achieve the most accurate volume possible.
VirtualSurveyor also offers several drawing modes — such as Free, Arc, and Guided Breakline— to help speed up the boundary drawing process and improve accuracy.
Choosing the correct stockpile reference level is key to producing reliable results. While freestanding stockpiles can often use On Terrain vertices, more complex scenarios — such as walled, overlapping, or banked stockpiles — require additional setup.
VirtualSurveyor provides several surface reference methods to handle these situations accurately:
- Freestanding
- Enclosed wall
- Open wall on a flat area
- Open wall on a sloped area
- Overlapping
- On a bank
Each method is designed to model the terrain beneath the stockpile as realistically as possible.
Create a Stockpile
To create a stockpile:
- Draw a boundary around the stockpile.
- Select the boundary.
- Choose the appropriate reference level from the dropdown options in the Volumes group of the TOOLS tab.
For more complex stockpiles, you can manually adjust boundary vertices or define additional surfaces to create the most accurate baseline under the stockpile.
Freestanding Stockpile
For freestanding stockpiles, draw a precise boundary around the pile, then use the 3D Surface setting to create the stockpile. The base surface is triangulated from the vertices of the stockpile boundary, which makes accurate Z values essential. The precise boundary ensures the triangulated surface reflects the true ground level.
After creating the stockpile, select it and enable the Transparency lens to visually validate the surface beneath the pile.
Freestanding stockpiles are calculated the same way whether they are on flat ground or on a slope.
Profile view of a freestanding stockpile
Profile view of a freestanding stockpile on sloped terrain.
Enclosed Wall Stockpiles
For enclosed wall stockpiles, select the Flat method and manually define the floor elevation under the stockpile.
To find a reliable elevation value, hover your mouse over the ground just outside the walled area. The Z value at your cursor location is displayed in the status bar. Use this value as the best estimate for the stockpile baseline. Once entered, create the stockpile.
Select the stockpile and enable the Transparent lens to see the surface under the stockpile
Profile view of an enclosed wall stockpile with the Flat surface setting
Tip: Cross sections can be created and densified on stockpiles to help analyze elevation changes and better understand pile geometry.
Open Wall Stockpiles on a Flat Area
For open wall stockpiles on flat ground, select the Flat Minimum setting. This creates a uniform reference surface using the lowest boundary vertex.
At least one vertex must be placed on the ground in front of the stockpile for this method to work correctly.
Use the Transparent lens to validate the surface beneath the open-walled stockpile.
Profile view of the open-walled stockpile using the flat minimum setting
Open Wall Stockpiles on Sloped Areas
When an open wall stockpile sits on sloped terrain, additional setup is required.
After drawing the boundary, manually edit the Z values of the boundary vertices to best approximate the underlying ground. Then use Interpolate Z to smoothly transition between the highest and lowest points and account for the slope.
This process is demonstrated step by step in the linked 2-minute video.
Once complete, create the stockpile using the 3D Surface setting and validate it with the Transparent lens.
Profile view of an open-walled stockpile on a slope
Overlapping Stockpiles
Overlapping stockpiles require careful boundary definition to clearly separate one pile from another.
Begin by drawing a boundary around the overlapping stockpile in 2D view mode, using On Terrain mode just as you would for a freestanding stockpile. Pay close attention when placing points along the overlap so each pile is clearly delineated.
Use Interpolate Z to set the boundary outline to the ground level beneath the overlapping area.
With the stockpile clearly defined from the other pile, create the stockpile using the 3D Surface setting and validate the baseline using the Transparent lens.
Stockpile on a Bank
To accurately calculate a stockpile on a bank, you must first model the terrain beneath it by creating a surface under the pile.
Start by drawing a boundary around the stockpile, then draw one or more breaklines that follow the toe of the bank under the pile. (Detailed step-by-step instructions can be found in the Calculate a Stockpile Over a Bank article.)
Interpolate the breaklines so they drop beneath the stockpile and use them to triangulate a surface that represents the underlying terrain.
Once the surface is defined, select it and click the Stockpile button. No additional surface setting is required. Same as the other stockpiles, you can always use the Transparent lens to validate the surface below the pile.
Profile view of stockpiles over a bank, gradient, and trench: Any type of stockpile that is over a bank, gradient, or trench will require a manually created surface under the stockpile by drawing a boundary around the stockpile then defining the baseline with breaklines drawn at the changes in the slope under the stockpile. VirtualSurveyor offers all the tools you need to make any kind of baseline drawing required.
A stockpile over a bank typically requires at least one breakline
A stockpile over a gradient typically requires at least 2 drawn breaklines to define the surface below the pile
Stockpile over a trench may require at least 4 breaklines to properly define the underlining terrain
Validation
Once your stockpile has been created, it’s always a good idea to validate the calculation before exporting results or sharing reports.
Stockpile accuracy depends heavily on the baseline surface beneath the pile. A quick validation step helps confirm that the reference level is correctly placed, especially for walled, overlapping, or banked stockpiles.
VirtualSurveyor includes several tools that make it easy to visually check your stockpile surface and ensure your volume results are reliable.
Extract the Surfaces of the Stockpiles
One of the best ways to validate a stockpile is to inspect the surface being used underneath it.
After creating a stockpile, you can use the Transparent lens to look through the material and confirm that the baseline matches the terrain or floor level you intended.
For more detailed review, you can extract the stockpile surfaces to better understand how the stockpile was modeled. This is especially helpful when working with:
- Open wall stockpiles
- Overlapping stockpiles
- Stockpiles built over banks, trenches, or uneven ground
By checking the extracted surface, you can confirm that breaklines, interpolated vertices, and reference elevations are producing the most accurate baseline possible.
Modify the Terrain for All Stockpiles
A Timestep can be used to remove stockpiles entirely and create an “Empty Site,” making it easier to visualize and analyze volume changes.
This is a powerful validation method when comparing stockpile surveys over time, especially when you want to confirm that the terrain beneath the piles is modeled correctly across multiple datasets.
See the Stockpiles at Eye Level and Walk the Project Site
Tips and Tricks
- Multiple stockpiles over time - Use Timesteps to compare stockpile surveys over time or contrast filled stockpiles with an Empty Site. Access the Timeline from the View tab or the calendar icon in the status bar. (Peak/Mountain users only.)
- Import stockpile boundaries - Import DXF files to define stockpile bases — especially useful for sites with fixed storage locations.
- Assign Materials - Assign materials from the Material dropdown in the TOOLS tab. Materials can be edited or changed at any time using the Material Editor.
- View stockpile information - Stockpile inventory details appear in the Selection box when a stockpile is selected. You can also recalculate stockpiles from here.
- Annotate stockpiles - Tick the Volume checkbox in the annotation settings found in the TOOLS tab when a stockpile is selected to display the net volume value in the Viewport over the stockpile.
- Create multiple stockpiles at once - Select multiple boundaries that share the same surface type and click Stockpile to calculate them simultaneously.
- Export results - Export stockpile data as PDF reports, CSV spreadsheets, or GIS files from the EXPORT tab. You can also create reusable export templates for layers and materials.
