How to created intersection line between 2 line projection - grading

[tehnicar]

 I have feature line with elevations that represents bottom of ditch and want to go UP 3:1 slope. also i have edge of road feature line that is higher than ditch  and want to go 2% down until it hits side of the ditch that is 3:1. could someone tell me the easiest way in civil 3d to create intersection line between ditch bottom going up 3:1 and edge of road going down 2%?

thanks!

[Neilw_05]

This can be handled by gradings. As long as gradings are in the same site they will interact with each other and form a featureline where they intersect.

All you need to do is create a grading down from the edge of road at 2% and a grading from the bottom of the ditch up at 3:1. I suggest you use a distance grading and specify a distance that ensures the 2 gradings will intersect each other.

Keep in mind that to make the road grading project DOWN you will specify a 2% FILL parameter. Likewise to make the ditch grading project UP you would specify a 3:1 CUT parameter.

[wfberry]

Neil:

That interacting feature is somewhat new, I believe.  Posters should be willing to share their setup for proper information.

(... stepping down from podium..)

Bill

[jb82]

Hi Neil, I have basically the same question as the original poster but I'm wondering if there is a way to find that intersection without using grading objects at all. If I just want to use spot grades/feature line grading without messing with grading objects, is there a way to find that point?

I thought I may have found the tool in Civil 3D to do this  (it's under "points -> create points -> high/low point") but I was not successful in using it. I gave it a low point on my surface, then a high point, then I gave it a positive slope coming up from the low point and a negative slope coming down from the high point, thinking that it would then give me the location of the point between where the two slopes intersect. Unfortunately, it didn't work, I think maybe because it wants the point in between to either be lower than both points or higher than both points and not in between somewhere? That's my best guess.

Anyway, any help on this would be greatly appreciated!

[Neilw_05]

You can find the point using a featureline. Read the help topic: "To insert a High or Low Elevation Point on a Feature Line" under the "Grading"/"Editing Feature line Elevations" topic.