To Add Free Vertical Curves to a Profile

To add a free circular vertical curve between elements

Add a free circular vertical curve between two straights by specifying a parameter. Select a pass-through point in the drawing or specify a length or radius to define the curve.

Note: This type of curve cannot be created between two curves or between a straight and a curve.

The illustration shows a free circular curve between elements 1 and 2, passing through point 3.

1. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
2. On the Profile Layout Tools toolbar, click Free Vertical Curve (Circular).
3. Select the first fixed or floating element to which you want to attach the curve.
4. Select the second fixed or floating element to which you want to attach the curve.
5. Enter one of the following parameters to complete the curve definition:
   • Pass-Through Point: Enter P
   • Radius: Enter R
   • Length: Enter L
   • K Value: Enter K
   Note: If the profile was created using the criteria-based design feature, a default value is displayed on the command line. Minimum K values at given design speeds are specified in the design criteria file. Minimum curve length and radius are calculated from the minimum K value at the current design speed.

To add a free parabolic vertical curve between elements

Add a free parabolic vertical curve between two elements by specifying a parameter. Select a pass-through point in the drawing or specify a K value, length, or radius to define the curve.

The illustration shows a free parabolic curve between elements 1 and 2, passing through point 3.

1. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
2. On the Profile Layout Tools toolbar, click Free Vertical Curve (Parabolic).
3. Select the first fixed or floating element to which you want to attach the curve.
4. Select the second fixed or floating element to which you want to attach the curve.
5. Enter one of the following parameters to complete the curve definition:
   • Pass-Through Point: Enter P
   • Radius: Enter R
   • Length: Enter L
   • K Value: Enter K
   Note: If the profile was created using the criteria-based design feature, a default value is displayed on the command line. Minimum K values at given design speeds are specified in the design criteria file. Minimum curve length and radius are calculated from the minimum K value at the current design speed.

To add a free VIP-based parabolic vertical curve

Add a free parabolic vertical curve. Specify the curve by length, a pass-through point, or a K value.

The illustration shows a free curve between elements 1 and 2, specified with a length parameter 3.

1. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
2. On the Profile Layout Tools toolbar, click Free Vertical Parabola (VIP Based).
3. In the profile view, select a location near the VIP to which you want to add a curve.
4. Enter one of the following parameters to complete the curve definition:
   • Length: Enter L.
   • Pass-Through Point: Enter P
   • K Value: Enter K.
   Note: If the profile was created using the criteria-based design feature, a default value is displayed on the command line. Minimum K values at a given design speed are specified in the design criteria file. Minimum curve length and radius are calculated from the minimum K value at the current design speed.

To add a free VIP-based asymmetrical vertical curve

Add a free asymmetrical vertical curve. You specify the length of the curve before the VIP and the length of the curve after the VIP.

The illustration shows an asymmetrical curve between straights 1 and 2, with curve lengths 3 and 4.

1. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
2. On the Profile Layout Tools toolbar, click Free Asymmetrical Parabola (VIP Based).
3. In the profile view, select a location near the VIP to which you want to add a curve.
4. Specify the length of the curve before the VIP by entering a value or by selecting two points in the drawing window.

   If the first length you specify is too large for the asymmetric curve, you cannot enter the length for the second curve. The length of the first curve must be less than the chainage distance between the VIP you select and the chainage value of the previous VIP (or end chainage of the previous curve.)

5. Specify the length of the curve after the VIP by entering a value or by selecting two points in the drawing window.
   Note: If the profile was created using the criteria-based design feature, a default value is displayed on the command line. Minimum K values at given design speeds are specified in the design criteria file. Minimum curve length and radius are calculated from the minimum K value at the current design speed.

To add a free VIP-based circular vertical curve

Add a free circular curve. Specify a radius, length, or pass-through point to define the curve.

The illustration shows a circular curve at VIP 1, passing through point 2.

1. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
2. On the Profile Layout Tools toolbar, click Free Circular Curve (VIP Based).
3. In the profile view, select a location near the VIP to which you want to add a curve.
4. Enter one of the following parameters to complete the curve definition:
   • Radius: Enter R.
   • Length: Enter L.
   • Pass-Through Point: Enter P.
   Note: If the profile was created using the criteria-based design feature, a default value is displayed on the command line. Minimum K values at given design speeds are specified in the design criteria file. Minimum curve length and radius are calculated from the minimum K value at the current design speed.

To add a free vertical curve by best fit

Add a free, three-point curve element by best fit to a profile. You can define the best fit element using a series of Autodesk Civil 3D points, existing elements, or clicks on screen.

The illustration shows a free vertical curve created by best fit between endpoints 1 and 2. The Xs indicates data points used to create the element.

Note: Each best fit profile element is drawn to the vertical scale set in the profile view style. To create an accurate best fit element, set the profile view style Vertical Exaggeration value to 1.000 to match the horizontal scale of the profile view.

1. Set the profile view style Vertical Exaggeration value to 1.0000.
2. Click the profile. Click Profile tabModify Profile panelGeometry Editor Find.
3. On the Profile Layout Tools toolbar, click Free Vertical Curve - Best Fit.
4. Select an existing fixed or floating profile element (the First Element) from which to attach the best fit straight.
5. Select an existing fixed or floating profile element (the Next Element) to which to attach the best fit straight.
6. In the Curve by Best Fit dialog box, select one of the following:
   • From COGO Points. In plan view, select two or more points. Enter G to select a point group or N to enter points by number.
   • By Clicking On The Screen. Select a starting point and at least one other point. You can use OSNAP or transparent commands to select points.
   • From Elements. Specify the tessellation and mid-ordinate tolerance settings. You can select one or more of the elements types listed on the command line. If you selected a profile element, specify the starting and ending station on the Specify Station Range dialog box.
   As you select points or elements in the drawing window, an X marks each regression point and a temporary, dashed curve is displayed in real time. Press Enter to complete the command.
7. In the Panorama window, use the Regression Data vista to modify the regression points.

   As you highlight a row in the Regression Data vista, the corresponding regression point in the drawing window is highlighted in red.

8. Create the curve:
   • Click to create the curve and keep the Regression Data vista open.
   • Click to create the curve and close the Regression Data vista.