Mass Calculation - Cross Section Method - Define Mass Types

Mass Types

The function Create... can be found in the Mass Types tab in the properties dialogs for SFI model, intersection, and excavation. For SFI models, it is most practical to use a longitudinal profile/cross section as a starting point when defining a new mass type. One of the advantages of this is that we can see the result of the rule directly in the profile.

Tip

If you want to create a new mass type with the same definition as an existing one, you can use Create Derived.... For SFI models, we also find the option New Composite... in both the properties dialog and cross section view (not active for mass types in longitudinal profile).

When we define a new mass type, the name is the first thing we enter. If we have Gemini QuantiFlow activated, or a local contract for the project, we can link the mass type to a contract post code. Import of contract posts can be done in the dialog Settings Gemini Terrain... - Project - Contract Posts.

Next, we must choose a calculation type. We can choose between the following calculation types:

Calculation Type	Longitudinal Profile	Cross Section	Integral Method (intersection and excavation)
Area horizontal	x	x
Area diagonal	x	x
Area thickness		x
Area vertical	x	x
Flat area		x
Contour drilling		x
Length horizontal	x
Length diagonal	x
Polygon		x
Volume		x	x
Volume difference		x
Volume intersection		x
Volume union		x

When the calculation type is selected, we need to define the rule itself. The principle is the same whether we are talking about layers in the cross section or layers in an excavation. Available options for the different calculation types vary. Below you will find several examples of how to use these.

Area Calculation

Area Horizontal, Area Diagonal, and Area Vertical

For calculation types Area horizontal, Area diagonal, and Area vertical, we select which layer to use in the field Area layer. Area layers can be both physical and theoretical layers.

For all area layers, we can also specify Over layer and Under layer.

Example

This example shows the cleaning of the rock surface. In this case, we want to calculate the area of the rock layer that is above the subgrade. The solution is to use Over layer to find the extent.

Figure: A = Cleaning of rock surface

Cleaning of the rock surface is defined as follows:

• Area layer:

Phys. 6: Rock

• Over layer:

Theo. 1: Subgrade

In the example above, we have one area layer. In this case, the methods Highest, Lowest, and End/end don't matter. We only need to consider the method when we have selected two or more layers.

Flat Area

The calculation type Flat area is a bit special. According to NS3420, a flat area is an area of rock with a height < 1.0 m. The blasting volume is calculated from the actual polygon (blue shaded area). Beyond this amount (fm³), a supplement is given for the additional cost of flat blasting.

Figure: A = Flat area

Flat blasting is defined as follows:

• Area layer:

Phys. 6: Rock

• Under layer:

Theo. 1: Subgrade(+1.000m)

Theo. 2: Deep blasting(+1.000m)

• Over layer:

Theo. 1: Subgrade

Theo. 2: Deep blasting

Info

In the example above, we see that some of the layers have (+1.000m) after the name. This is one of the advanced settings we can make on layers. Double-click on a layer in the list and you will get a dialog to set advanced settings.

Volume Calculation

Mass Balance Factor

Under the Mass Balance tab, a Factor for mass balance can be entered.

Note

If we enter a value for mass balance, the columns Balance and Accumulated Balance in the mass report will be corrected with this factor; all other columns are fixed masses.

Minimum Thickness

For mass types with Volume as the calculation type, we can specify a Minimum Thickness. If we enter a value for minimum thickness, this will be the minimum thickness in the calculation. How this affects the mass is illustrated in the example below.

Example

According to the process code, the rule states that rock height under 1.0 meter should be counted as 1.0 meter (fm³). Volume is then calculated based on the sum of blue and red polygons.

Figure: A = Minimum thickness

Area Thickness

With this option, we can calculate a volume based on an Area layer and a Thickness.

Volume

For the calculation type Volume, we must specify From layer and To layer to be included in the calculation.

If we have multiple from layers and/or to layers, their relative positioning matters. In these cases, we need to consider the options Highest and Lowest.

Example

Figure: Mass type for soil cutting. A = Road surface (dotted), B = Subgrade (blue layer), C = Soil, D = Rock

In this case, we have rock and subgrade as From layers and soil as To layer. For the from layers, we have chosen Highest, which means that the highest of rock and subgrade applies.

Soil cutting is defined as follows:

• To layer:

Phys. 1: Soil

• From layer (highest):

Phys. 6: Rock

Theo. 1: Subgrade

Volume Difference, Volume Intersection, and Volume Union

For the calculation types Volume difference, Volume intersection, and Volume union, we must specify which layers will form Polygon1 and Polygon2. We see that the order of the layers in the list is important if we have more than two layers. The layers should follow each other, and the positive direction is clockwise. Layers with a negative direction must be reversed in the mass type. This is set under advanced settings for the layer, and the option is marked with a dash (-).

Note

For calculation type Union, it is possible to specify only Polygon1.

Example

In this case, we want to define the polygon for the tunnel blasting profile. It consists of the layers for tunnel blasting profile and subgrade. The default direction for subgrade is from left to right. We see that the direction must be reversed (advanced settings on the layer). The polygon for the blasting profile is therefore defined as follows:

• Polygon1:

Theo. 31: Tunnel blasting profile

Theo. 1: Subgrade(-)

Polygon

There will always be situations where we cannot calculate the volume we want with the methods described above. Therefore, a calculation type Polygon has been created to solve "impossible" situations.

Procedure

Procedure

1. Create a new layer
2. Manually enter the desired polygon in the cross section
3. Create a new mass type
4. Define the mass type with calculation method Polygon and Polygon layer

Composite Mass Type

Composite mass types are used to calculate mass types in cross sections against each other using the methods Volume difference, Volume intersection, and Volume union. This way, for example, you can calculate backfill material minus volume for pipes in trenches with large pipe dimensions by first calculating the backfill material in one mass type and the amount for the pipe in another mass type. Then you create a composite mass and use Volume difference to calculate the backfill material minus the pipe.

Other Settings

Restriction Layer

The restriction layer gives the maximum horizontal extent for the mass type in the profile. If a restriction layer is defined for the mass type and it does not exist in a profile, no masses will be calculated there.

We can also add an extension for the restriction layer. If we want different extensions on the left and right sides, we enter both values separated by a colon, for example, 1.000:2.000. This functionality is not active for mass types in excavation and intersection.

Example

The road determines how far out we should calculate vegetation clearing (A).

• Area layer:

Phys. 99: TOP PHYSICAL LAYER

• Restriction layer:

Theo. 0: Surface

Info

We can also use lines to limit the mass type. These lines must be defined as extra lines in the SFI model. To define these lines, we must use the function Extra Lines... on the toolbar.

Note

For excavation and intersection, we cannot use physical layers as restriction layers. If we want to use, for example, the extent of measured rock, we must copy the boundary contour onto a layer in the excavation.

Treat All Layers as Theoretical

When we define our own mass types, the rules for theoretical layers are often the most logical for the user. Based on this, a separate option Treat All Layers as Theoretical has been created.

How the program calculates the extent of the mass type will in some contexts depend on whether it is physical layers or theoretical layers in the definition.

We can show this most easily with some examples. The red hatching shows the calculated amount.

Area Calculation

Figure: Only theoretical layers. A = Under layer, B = Over layer, C = Area layer

Figure: Only physical layers. A = Under layer, B = Over layer, C = Area layer

Volume Calculation

Figure: Only theoretical layers. A = To layer 1, B = To layer 2, C = From layer

Figure: Only physical layers. A = To layer 1, B = To layer 2, C = From layer

Calculation Area

For mass types in longitudinal and cross-section profiles, we can specify which profile intervals the mass type should apply to (tab for calculation area). We can have multiple intervals for a mass type. Enter the profile intervals directly in the list.

If we enter an asterisk (*) before the profile number, this means we have a 0-profile. A 0-profile means that the mass is 0 in this profile. How 0-profile is handled is described in the section on calculation method. 0-profile is only active for mass types in cross section.

The figures illustrate different alternatives that can occur for the end of an interval. The same applies for the start. The color symbolizes which profile the masses belong to. The profiles that exist are numbered on the X-axis.

Figure: Profile interval From: 60 To: 88

Figure: Profile interval From: 60 To: 88 (zero-profile)*

Figure: Profile interval From: 60 To: 90

Figure: Profile interval From: 60 To: 90 (zero-profile). Special case where the to zero-profile is a profile that exists, but there will be no masses in this profile.*

What Happens If We Specify Profile Numbers Outside the Line?

Often we want to extrapolate the interval for the mass type at the beginning and end of the line, for example for trenches.

We do this by specifying the desired profile before and after. This functionality only applies to mass types in the cross section.

Figure: Extrapolation of last profile. The last profile is profile 100, but profile interval in mass type From: 80 To: 107.

Figure: Extrapolation of last profile. The last profile is profile 100, but profile interval in mass type From: 80 To: 107 (zero-profile).*

Create Layer from Mass Type

The layer is built when the mass type is calculated and gets the same number. This means that the layer cannot be used in mass types with lower numbers. The functionality can, for example, be used to calculate blasting masses based on drill depths.