Special Grading (VIPS Method)¶

Use this dialog to define:

Layers in the superstructure (independent of the road surface)
Layers for deep blasting
Layers for landscaping

Where can I find the dialog?¶

In the toolbox, select SFI Properties..., and go to the Road Body tab.

Using the dialog¶

The layer is built up of surfaces separately for the left and right sides of the centerline. They have different rules for the starting point. The surfaces are specified with width and slope, and there are several methods for specifying these. The ending can be performed either automatically or by using an end surface.

The function supports building special grading on only one side of the centerline. In earlier versions, special grading had to be defined for both sides. For example, the superstructure can be built from special grading on one side and from the superstructure table on the other.

The dialog has a dedicated preview window, as well as the ability to change which profile you want to view.

Note

It is not possible to zoom in the preview window. In cross-section editing, there is also a preview directly in the cross-section, where you can zoom and, for example, measure distances. Material types are also updated when editing the table.

Starting Point for Special Grading¶

Layers in the Superstructure¶

The layers in the superstructure start at the centerline. You do not need to specify the depths; these are automatically calculated based on the thicknesses given in the superstructure table.

In the construction settings, you can check for minimum superstructure thickness. With this option, the program will check that no part of the layer has less thickness within the surfaces (-3.99:3.99) after construction. If the criterion is not met, the layer will be adjusted.

Layers for Deep Blasting¶

The layer for deep blasting starts at the centerline. For deep blasting, you specify the minimum depth, which becomes the value for the starting point. The road surface is the reference surface for the depth.

Figure: A = Min. depth

In the Settings dialog, you can check Check minimum depth. With this control enabled, surface 1 (both left and right sides) in the deep blasting layer is checked against the surface layer. If the minimum depth is not satisfied for this part of the deep blasting layer, it will be adjusted down.

Note that the depth you specify at the center applies to the center even if you only have deep blasting on parts of one side.

Figure: A = Min. depth

Layers for Landscaping¶

The starting point for landscaping can be defined by the following methods:

Height (absolute)
Vertical distance from centerline

Figure: A (thick blue line) = Vertical distance

Horizontal distance from centerline

Figure: Thick blue line = Horizontal distance

Surface (outer edge)

Figure: Blue dot = Outer edge surface 2.01

For methods 1-3, the program uses the first surface outside the shoulder edge that intersects with this height/distance.

Shaping Surfaces in the Layer¶

For all layers, you can shape the grading surfaces differently on the right and left sides of the centerline, and you can have as many surfaces as you want. Select Insert with the right mouse button in the surface column to create new surfaces. Surfaces are numbered consecutively from 1 and up. The menu also has an option to insert an end surface.

The example shows three surfaces and an end surface.

Note that for layers in the superstructure, you can only insert an end surface for the bottom layer (Planum).

The surfaces in special grading are described with width (m) and slope (decimal number). The surface description refers to the profile number, and if width and/or slope is changed between two rows, the program will interpolate values linearly. Note that you have several methods for specifying width and slope.

Width¶

You can determine the width in three different ways:

Width in meters (Width method 0)
Width from surface (Width method 1 and 2)
Width from line (Width method 3 and 4)

You must set the Width method yourself. Double-click in the column, and the options for width method will be available in the dropdown list. The width method determines which column the program retrieves information from. Note that width method 1 and 2 currently work the same way. Width method 3 and 4 require that there are extra lines you can refer to.

With Ray slope and Extension, you can define additional widths for the grading surface. They can be used independently of each other. The figures below show different options based on deep blasting.

Figure: A = Width in meters

Figure: A = Surface (-2.01)

Figure: A = Line (ID 1)

Slope¶

Slope can be defined in three ways:

Slope as a decimal number (Slope method 0)
Slope as road surface (Slope method 1 and 2)
Slope as bottom of superstructure (Slope method 3)

In the Slope method column, you determine which method to use. The Slope/Surface column contains the values used by the slope method. For slope method 0, you enter the slope, while for slope method 1 and 2, you enter the road surface. The figures below show different options based on deep blasting.

Figure: A = Slope as a decimal number

Figure: A = Slope from road surface (-1.01)

Figure: A = Height from line

End Point for Special Grading¶

Layers in the Superstructure¶

Normally, special grading will end when it intersects with ditch or fill surfaces. If special grading is lower than the bottom of the ditch or fill, the program will not find an intersection, and you must use an end surface. The top seven superstructure layers are first trimmed against the road surface. If Planum is specified, they are then also trimmed against this.

Layers for Deep Blasting¶

Without using an end surface, the layer will be extended to the first 5-surface, or to the intersection with the extension of this. The figure below shows an example of this automation.

Figure: A (blue line) = Automation

Layers for Landscaping¶

The end point for landscaping can be specified in two ways:

First intersection with the terrain:

Figure: 1-3 = Surface 1-3, A = Landscaping

Last surface's intersection with the terrain

Figure: 1-3 = Surface 1-3, A = Landscaping

You set this up under the end method for the starting point. Using an end surface is not as relevant for landscaping.

Using an End Surface¶

If you use an end surface, you have full control over where the grading ends. Select Insert end surface with the right mouse button in the surface column. For end surfaces, the text in the Width method column changes to End surface method.

An end surface can be described in four ways:

Calculate end point
Calculate slope
Calculate starting point
Extrapolate last surface

Calculate End Point¶

With the Calculate end point method, the program calculates the end point based on the given slope, i.e., the intersection with the trough, or the top physical layer. You enter the value for the slope in the Slope/Surface column.

Figure: A = Calculate end point

Calculate Slope¶

With the Calculate slope method, you enter a road surface. The slope is calculated so that the end point in the road surface becomes the end point in the end surface. You enter the value for the road surface in the Surface column.

Figure: A = Calculate slope

Calculate Starting Point¶

With the Calculate starting point method, you enter the slope and road surface. Based on these values, the starting point for the end surface is calculated. At the same time, the width of the inner surface is adjusted to this starting point. You enter the value for the road surface in the Surface column and the value for the slope in the Slope/Surface column.

Figure: A = Calculate starting point

Extrapolate Last Surface¶

The Extrapolate last surface method gives the standard ending, i.e., the same as without using end surfaces.

Example – Planum Layer in the Superstructure¶

The example shows different options that can be used for the Planum layer in the superstructure.

In the example, old VIPS coding is used, -1.1, -2.1, etc.

Surface 1¶

Figure: A = Extension B = Ray

Surface 2¶

Surface 3¶

End Surface¶

Figure: A = End surface