I have a feature line that is below the surface of an existing earth dam embankment. I want to grade downward from that feature line at a shallow slope until it daylights somewhere down the embankment slope. How do I accomplish this? All I can get it to do is slope upward (cut) to the existing surface.
Solved! Go to Solution.
Solved by Neilw_05. Go to Solution.
Can you post a picture? I can't see why it couldn't be done when I sketch you description.
One option is to over grade at you slope make a surface, compare and plot the zero contout to find you daylight.
Look at the help file for the setting shown in this screen capture.
Here is what you do. Create a temporary surface with the slope you are looking for from the feature line. Make sure that temporary surface extends beyond the limits of the earthen dam.
Then create a TIN volume surface between the earthen dam and your temporary surface. use a surface style on the volume surface you can see contours on. Create a user defined contour at elevation 0. This will be the intersection between you temporary slope and the earthen berm.
Extract the 0 elevation contour and use it to get elevations from your earthen berm surface. Add it to a new surface with your original feature line... There you go!
@d1of2 wrote:Here is what you do. Create a temporary surface with the slope you are looking for from the feature line. Make sure that temporary surface extends beyond the limits of the earthen dam.
Then create a TIN volume surface between the earthen dam and your temporary surface. use a surface style on the volume surface you can see contours on. Create a user defined contour at elevation 0. This will be the intersection between you temporary slope and the earthen berm.
Extract the 0 elevation contour and use it to get elevations from your earthen berm surface. Add it to a new surface with your original feature line... There you go!
You could also omit the italicised section and simply use the MinimumDistBetweenSurfaces tool (best used in 2012/2013 as this creates a 3D polyline but 2011 can be used with a little more work)
neilyj (No connection with Autodesk other than using the products in the real world)
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Guys, I think you are making this far too complicated. All you need to do is change that search order setting to Fill First and the grading will then look for a solution downward rather than upward when in cut.
Good one Neil, I never saw that setting
I appreciate the responses. My immediate need was solved by setting fill first. There are other issues with trying to grade this project that have me reaching for the gun. I was doing this type of stuff easily with simple add-on tools twenty years ago. Why simple tasks have to be so complicated in Civil 3D is beyond me. Sorry, had to vent! I do appreciate the help.
They really meant it when they said forget everything you new about (LDT) or other apps; didn't they?
One thing that I have adopted and has been working for me is compartmentalize grading. I no longer look for the finished product from one tool or one pass of a grading app, but start off thinking in very general terms and refine as I go.
If you set out setting final grades in your first pass you are only setting yourself up for disappointment. Look at it like a big block and chisel away small pieces at a time.