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Table Of Contents
Chapter 3 Working with Profiles and Vertical Alignments
226
Drawing a Vertical Curve Based on an
Elevation Point
To draft a vertical curve based on an elevation point
1 From the Profiles menu, choose DT Vertical Curves to display the Vertical
Curves dialog box.
2 In the Description list, select the High/Low Point option. You can also click the
High/Low Point icon, and then click OK.
3 Select the tangents that represent the grades into and out of the PVI.
4 Select the high/low point by doing one of the following:
n
Select a point in your drawing.
n
Press ENTER and entering a numeric value for the elevation.
The command computes the necessary length of curve to pass exactly through
the given point.
5 Press ENTER to accept the length of curve required to pass exactly through the
given point, or enter a new length.
If you change the length, then the actual curve passes above or below the
given point.
The High/Low option then displays the high/low station and elevation for the
curve drawn. If you cannot calculate a high or low point for the selected
tangents, a No high or low point exists for this curve message appears.
The following illustration shows the parameters used in calculating a vertical
curve based on high/low elevation point:
Drawing a vertical curve by elevation point
Drawing a Vertical Curve through a Point
To draft a vertical curve that will pass through a selected point
1 From the Profiles menu, choose DT Vertical Curves to display the Vertical
Curves dialog box.
2 In the Description list, select the Through Point option. You can also click the
Through Point icon, and then click OK.
3 Select the tangents that represent the grades going into and out of the PVI.
4 Pick the point the vertical curve will pass through, or press ENTER, and then
enter a station number and elevation.
The length of the curve is calculated.