Volume Presets

The Volume Definition Editor includes a Preset dropdown that populates the term builder with common volume configurations. Presets provide a quick starting point – after applying a preset, you can modify the terms, change line selections, or add additional terms to customize the definition.

Available presets

Overbreak

Measures the excess excavation beyond the design template – the area of the measured profile that extends outside the theoretical line.

  • Formula: Area(Excavation, Template)

  • Term type: Area (intersection)

  • Lines: first measured line definition + first template line definition

  • Use case: quantifying over-excavation for cost analysis and shotcrete consumption

Note

The intersection-based Area() function captures only the overlapping region. To measure specifically the area outside the template, use DiffArea(Excavation, Template) instead.

Underbreak

Measures the area of the design template that was not excavated – the violation zone where the measured profile falls inside the theoretical line.

  • Formula: Area(Template, Excavation)

  • Term type: Area (intersection)

  • Lines: first template line definition + first measured line definition

  • Use case: identifying zones where the tunnel profile does not meet the design specification

Full Excavation

Measures the total area enclosed by the measured excavation profile.

  • Formula: EnclosedArea(Excavation)

  • Term type: EnclosedArea (single polygon)

  • Lines: first measured line definition

  • Use case: total cross-sectional area for material quantity estimation

Shotcrete Thickness

Measures the area between two measured lines – typically the excavation line and a shotcrete line. This represents the cross-sectional area of the applied shotcrete layer.

  • Formula: Area(Excavation, Shotcrete)

  • Term type: Area (intersection)

  • Lines: first and second measured line definitions

  • Use case: shotcrete volume computation for material tracking

Tip

For shotcrete thickness, the intersection of the two measured lines gives the area of the shotcrete layer. If you need the full ring between the two lines, use DiffArea(Excavation, Shotcrete) instead.

Invert Area

Measures the area at the bottom of the tunnel section, below a specified elevation level.

  • Formula: EnclosedArea(Excavation) with Down clipping level enabled at 0.0

  • Term type: EnclosedArea (single polygon) with clipping

  • Lines: first measured line definition

  • Use case: invert concrete volume, drainage channel area

After applying this preset, adjust the Down clipping level to the actual invert elevation for your tunnel.

Crown Area

Measures the area at the top of the tunnel section, above a specified elevation level.

  • Formula: Area(Excavation, Template) with Up clipping level enabled at 0.0

  • Term type: Area (intersection) with clipping

  • Lines: first measured line definition + first template line definition

  • Use case: crown shotcrete area, arch support zone analysis

After applying this preset, adjust the Up clipping level to the actual springline or crown elevation for your tunnel.

Modifying presets

When you select a preset from the dropdown, it replaces the current term configuration entirely. The preset dropdown then resets to “Custom” to indicate that any further changes create a custom definition.

You can freely modify a preset after applying it:

  • Change the line selections to reference different measured or template lines

  • Add additional terms with the Add Term button

  • Adjust clipping levels or the additive constant

  • Switch the computation method between Applicable Length and Average Areas

Creating custom definitions

If none of the presets match your needs, leave the preset dropdown on “Custom” and build the formula manually using the term builder. Common custom definitions include:

  • Net lining area: DiffArea(Final Lining, Excavation) – the designed lining zone

  • Combined area: Area(Excavation, Template) + DiffArea(Excavation, Shotcrete) – multiple terms combined

  • Side-specific analysis: any term with Left/Right clipping to analyze one side of the tunnel independently