How to calculate earthworks?

Volume Calculations Using the Model-to-Model Method

First, ensure you have successfully completed the construction of two surfaces. For surface construction, see this page.

Activate the General Earthworks window. From the main menu bar, select: Earthworks → General. The "General Earthworks" window will open on the right.

It should be noted that CivilCAD software has several methods for earthworks calculations. Differences will necessarily arise between the various calculation methods, each with its own advantages and disadvantages. The first method presented here is the most accurate and hence its name "the accurate method." The disadvantage of this method is the difficulty in proving the calculation. In this method, there is no tracking of the way quantities are calculated (by the user), which can be problematic when submitting these quantities for supervision purposes, for example. Its alternative is the grid method.

As mentioned, you have several operational methods and calculation methods:

First, select the two surfaces for which the volume difference will be calculated. You can define any two surfaces that exist in the Surfaces list under the option: Calculate between.

General Earthworks Calculation Without a Grid ("the accurate method")

In the opened window, click the Apply button. The software will calculate the differences between the two layers (the existing condition model and the planned condition model) for the entire project and display a volume report including: excavation volume, fill volume, excavation area (approximate), fill area (approximate).

Grid Method

Check the ✅ box next to the Create full grid field in the right window. In the “Grid's steps” fields, enter the grid intervals in the X and Y directions (default is 10X10). Click the Apply button in the window. The software will calculate the volumes for the entire project using the grid method. The grid division will appear on the drawing, and in addition, the software will generate a quantity report indicating the excavation and fill volume for each square, intermediate summaries for every 10 squares, and the total quantity concentration for the entire project. Differences in calculation will exist whether "V" is marked next to Create full grid or not. To obtain an accurate result even when marking "V" next to this text, also mark "V" next to Use accurate system (this text will appear in the window only when the Create full grid option is checked) and click Apply.

Defining the Volume Calculation Area

In both methods just seen, the quantity calculation for the entire project was presented. In general, the calculation area will be determined according to the delineation of the planned contour lines. However, sometimes for aesthetic and other reasons, we will want to reduce the grid (including reducing the accompanying report) to a defined area where volumes for earthworks will be calculated. To do this, you can use the following buttons:

- Pick: In the selection box on the right, go to the drawing area and define the desired boundaries for the calculation. To finish defining the boundaries, click the "Set" button on the right (you can type "S" in the ACAD command line). Note that to change the calculation boundaries, you can mark one of the points in the point list on the right, click Pick again, and go to the drawing area. The software will draw a line from the point you pointed to, so the new boundary points will be added after this point.

- Select: Draw a Polyline that will define the calculation area, select Select in the selection box on the right, go to the drawing area, and choose the drawn Polyline. Then press Enter.

Now click Apply. The software will calculate the volumes according to the defined method only in the selected area.

Note: The Polyline must be constructed from segments without arcs or radii.

Volume Balancing

The Add to design field is primarily intended for balancing earthworks for a planned project. Such a project can be a water reservoir, planned surfaces, or planned contour lines according to elevation points. Use this field by entering the desired height addition for the project (in meters) and clicking Apply. The software will calculate and display a new report with quantities calculated so that the project's design is higher than the original design by the entered height addition. To reduce the project height, enter a negative addition (e.g., "-1.05"). In this way, by changing the project's planned height, you can easily achieve earthworks balance without changing the physical heights.

Note: In the obtained quantity report, the ratio between excavation and fill in the project is also shown. This data allows easier tracking of the achieved balance.

Stripping Earthworks

Stripping depth - to calculate volumes in a project where ground stripping is to be done, enter the stripping depth (in meters) in the excavation area (.Cut ar) and the fill area (.Fill ar), and click Apply. The software will recalculate the project's volumes and display a report including earthworks quantities after considering the entered stripping depth, including stripping volumes for excavation and fill.

Note: If there is no stripping in one of the areas (excavation or fill), leave the desired field blank or enter "0".

Defining Areas Excluded from Calculation

Often, there are areas where we do not want the software to calculate volumes. To define such areas, we need to ensure that CivilCAD does not create contour lines in them at all. This is because CivilCAD calculates volumes only in areas where there is an overlap between existing and planned contour lines. The best way to define an area as not to be calculated for volumes is to enclose it with a closed discontinuity line. It should be noted that a closed discontinuity line can be defined in both the existing and planned states, and wherever an area is defined by such a line, either in the existing or planned state (or both), the software will not calculate volumes for that area.

For detailed information on defining a closed discontinuity line, see the section on line connections in the line configuration settings.

Buttons in the Window

1. Locate calculation boundaries: Clicking this button will locate the volume calculation boundaries and color them yellow. After clicking Refresh (in the main toolbar), these boundaries will disappear. This way, you can locate the volume calculation boundaries you defined.

2. Delete boundary point: Select the point in the point list (in the upper window) and click the button. The point will be deleted from the list, and the calculation boundaries will be redefined. To confirm the action, click the Set button. Clicking Apply will recalculate according to the new boundaries. Using this action in conjunction with the Pick action allows you to edit the volume calculation boundaries as desired.

3. Delete calculation boundaries: After clicking the button, the software will warn that it is about to delete the defined calculation boundaries. After confirming the message, these boundaries will be deleted. If new boundaries are not defined, the next quantity calculation will be performed for the entire project area.

4. Display quantity report on the drawing: To display the quantity report on the drawing, perform the volume calculation, then click this button and place the table in the desired area of the drawing. By clicking the mouse in the intended place to create the report, a yellow frame will appear. If the table's location is as desired, enter "S" in the command line; otherwise, reposition the table. After clicking "S", a layer containing the desired report will be created.

5. Options button - General Earthworks window settings: This button will open the settings window related to the General Earthworks window. See below for detailed possible actions in this window.

6. Set boundaries: After entering the desired coordinates into the boundary window (at the top of the window), click this button to set the points as the desired calculation boundaries.