Add a floating reverse spiral-spiral-curve group, with a specified radius and pass-through point, to a curve.
The two spirals bend in opposite directions. The curve bends in the opposite direction of the attachment curve. When the attachment curve (1) is edited, the spiral lengths (2, 4), curve radius (3) and pass-through point (5) do not change. The attachment point and the length of the reverse curve adjust to accommodate edits to the attachment curve.
This entity does not support either of the following solutions:
- Solutions that require a floating curve angle greater than 180 degrees. The following illustration shows both the supported and unsupported solutions:
- Compound solutions. The following illustration shows an unsupported compound solution:
To add a floating reverse curve with spirals (from curve, radius, through point) off a curve
- Click the alignment. Click Alignment tab
Modify panelGeometry Editor
. - On the Alignment Layout Tools toolbar, click
Floating Reverse Curve With Spirals (From Curve, Radius, Through Point) to add a floating reverse curve with spirals off a curve. The current spiral definition is displayed at the command line.
- Specify the fixed or floating curve entity to attach to.
- Specify either the spiral in length or the A value.
Specify a new value, or press Enter to accept the value that is displayed on the command line.
- If the alignment has design criteria applied to it, the minimum value for the current design speed is displayed.
- If the alignment does not have design criteria applied to it, the default value specified in the curve and spiral settings is displayed. For more information, see Curve and Spiral Settings.
- Specify either the spiral out length or the A value.
- Specify the radius, or enter D to specify the degree of curvature.
NoteTo calculate the radius or degree of curvature using other known curve parameters, enter 'CCALC to open the Curve Calculator. For more information, see Calculating Curve Parameters.
- Specify the pass through point.