Grading Question

[GoJacks06]

Hi, I've been lurking on CADTutor for the last couple years and finally decided I need to join and ask some questions.

I'm working in Civil 3D 2013 and I'm trying to use the grading tool to fill a channel on a surface. My feature line is set at a 2.9% gradient and I just want the grading to be flat on both sides and tie into the existing grade. When I check a section view of my existing ground and my new grade line, my new grade is not flat like I thought it should be and it extends past the existing ground throughout the grading. Any ideas on how to clean this up so I get a new flat surface along my feature line that cleanly ties into existing ground? Thanks!

[sandiegophil]

Is there a chance you could post a pic or two?

 

Thanks,

Phil

[Bill_Myron]

I would use a corridor.

 

LinkSlopeToSurface on both sides would be perfect for this.

[GoJacks06]

Below is a screen shot of the existing ground contours. The cyan lines are my channel. I've got a profile line along the alignment at a higher elevation. As you can see the profile lines and contours in the grading are all over the place.

 

 

This is a quick profile view. As you can see the fill line is not flat like I had hoped and it doesn't end at the existing ground.

 

 

After seeing this, any suggestions? As far as a corridor goes, I haven't used them before. I'm guessing for a basic flat line like I'm looking for it wouldn't be too difficult would it? Would I be able to get fill quantities using the corridor feature? Thanks.

[sandiegophil]

it may sound odd but if you're more comfortable with grading than with a corridor you could join your 'channel lines' at each end, make a feature line from it and create grading infill from that. it would give you a cap to the extents of your channel.......

[GoJacks06]

The only problem there is that I don't want to fill just to the channel lines. I'd like to fill to a profile line with a specific gradient to it above that in most places and have that fill line extend to existing ground. Does that make sense?

[sandiegophil]

If you are trying to fill the channel to a specific elevation and add a cut/fill slope at each side I have to agree with bill below, a corridor is the most appropriate solution.

[GoJacks06]

Thanks for the advice. I'll see what kind of damage I can do with a corridor. Hehe.

[JerryG]

I agree - also with a corridor you could also place a 3dpoly line at specific elevations and grade

to that line.