Vertical Curvature

Before constructing the vertical curvature, a horizontal curvature must be created (see Horizontal Curvature). The vertical curvature is normally constructed in the longitudinal profile editing window, with a terrain longitudinal profile as background. You must therefore first create a longitudinal profile with the profile generator.

Elements in Vertical Curvature

The vertical geometry is built up of straight lines and circular arcs that are tangent to each other.

Info

Handbook V120 "Premises for Geometric Design of Roads" describes the theory around vertical curvature in detail.

Procedure

Procedure

1. Select the horizontal curvature in the map or command list.
2. Choose Generate longitudinal profile from the object context menu in the map.
3. Click Generate longitudinal profile.
4. Select the icon Vertical curvature (line overlay) on the toolbar.
5. Editing via the properties dialog is now started.
6. Construct the vertical curvature (the available functions are described below).

Note

The vertical curvature command can also be inserted in 2D view, where values can be entered.

Editing Methods: Properties Dialog and Grips

In Gemini Terrain, you can edit the vertical curvature in two ways:

• Properties dialog – precise, value-based editing. You can press Cancel to undo the changes you have made. Alternatively, you can ignore the changes in the properties dialog for the SFI model to retrieve the last saved state.
• Grips (grip handles) – fast, dynamic editing directly in the longitudinal profile, especially effective on existing lines. Grips editing cannot be undone with Cancel.

The icon to activate grips is on the toolbar.

You can turn dynamic helper lines – dynamic annotation and helper geometry – on/off with the icon at the bottom left of the toolbar.

Hide the dialog with [Ctrl]+[D]

The properties dialog takes up a lot of space, and it can be useful to hide it while editing the line geometry. Turn it on/off with [Ctrl]+[D]. [Enter] ends and saves the line (or click OK when the dialog is open). In editing mode, the various elements (straight line and radius) are highlighted with colors.

The rest of this chapter describes editing via the properties dialog. In general, you can double-click an object to open the properties dialog.

Functions on the Right Mouse Button

When you press the right mouse button in the map, a menu appears with the functions for dynamic editing. All functions have a hotkey – learning these saves you many keystrokes. The functions are described one by one below.

Exit and save

Ends and saves the line. Alternatively, you can use [Enter] or OK in the dialog.

Insert/change rounding

Used to insert roundings at an angle point. Select the point on the screen or in the dialog box (it is marked with a small cross), and the function is available on the context menu. Then enter the desired radius.

Lock gradient

With this option, you can lock the gradient of an element so that it has a fixed slope (+ or −) during editing. The element in front of the marked angle point is locked.

The slope is entered as a ratio. Locked elements are marked with an S in the properties dialog.

Insert point

Activates the mode for inserting points. When this is active, you can insert new points by pointing and clicking the left mouse button. In this mode, you can snap to helper lines/helper circles by holding [Ctrl].

Move point

Enables dynamic movement of a line via an angle point. Select the angle point on the screen and choose the function on the right mouse button. The curve points update continuously as you move the line.

Move radius dynamically

Allows dynamic changing of the radius. To set a fixed radius, Insert/change rounding is recommended.

Connection to Road Standards (Road Dimensioning)

When you select a dimensioning class for N100 under road dimensioning, a connection to the road standards is established when editing the vertical curvature. All road classes in the road standards have their own design table with requirements for, among other things, the vertical curvature.

The requirements in the design tables show that the vertical curvature depends on the radius in the horizontal curvature. This relationship is not automatically maintained during line construction.

The minimum value is used for roundings and the maximum value for gradient. When helper lines are activated, the maximum value for gradient is shown, and the dynamic line turns red if this value is exceeded.

Tip

You can run a complete check of the finished road. It also checks the dependency between horizontal and vertical curvature.

Next Step

Once the vertical curvature is in place, you define and generate the cross-sections. See the overall work process for road design.