Trouble with cut/fill and slope volume calculations

[TECADGUY]

I'm looking to create a surface or volume from a set of points. Within the boudary I need the elevation to all be calcualted to the same elevation, but outside the boudary I need it to daylight to the existing grade with a 3:1 slope. So one flat surface with slopes daylighting from the boundary to the existing.

I've tried the Grading function, which calculates either the interior or exterior, and have done a Tin Volume Surface. But that only calculates within the boudary I create, and doesnt create the slope to daylight to existing grade. I also was wondering if there was a way to pick only certain sides of the boudary to slope?

I've attached a file with a basic setup to better depict the issue at hand. Any help is greatly appreciated.

[aecoursen]

Using the grading tool I was able to get most of it graded, but they're areas that do not have a solution for 3:1 slopes meeting the existing surface.  You'll need to either increase the area of the existing surface, steepen the slope, or lower the constant elevation until you have a solution.  And yes you can select varying lengths and/or sides to grade.

[Pointdump]

Rob,

I opened your drawing, and it looks like a 3:1 slope daylights outside of your surface boundary.

You can pick a portion of your base footprint to grade from. After you pick a side to grade to, it will ask if you want to apply the grading to the entire length. Click No and you can pick points or type in stations. You can also Transition from one grading to another.

Dave

[TECADGUY]

Okay so the Grading tool is what I need to work with? And yeah I noticed the slope in some areas was not projecting out, will the model do that when there isnt enough data to daylight to? And if so, is there a way to just force the projection to the outer most data point?

My main issue was I wasnt able to get the area within the boundary to show the cut/fill contours and how they would tie in to the slope once it daylights. how were you able to do this?

Thanks again

[aecoursen]

The grading tool is what I used, but can be wonky over time.edits, as in it may disappear.  Less likely here as you have a simple purpose. And yes, if the grading tool can't find a solution, it will not provide one since it does not meet the criteria assigned in those areas. I don't believe you can target anything other then an elevation or surface with grading groups.  You could manually add a feature line(s) in the gap areas to complete the surface. 

You need to make sure you use an infill within the closed area to complete the surface.

[Pointdump]

Rob,

The grading criterias kinda limit you to grading to distance, elevation, relative elevation, or surface. You'd have more options by grading with a corridor. You could convert the surface boundary to a feature line and grade to it. But grading with a corridor is a lot more complicated.

Dave

[TECADGUY]

Ok. I'll have to look into the corridor tool further. But I was able to get started on the right path with the grading tool, thanks to all your tips.

Appreciate the help.

[Pointdump]

Rob,
An excellent book that covers grading very well is Ascent's AutoCAD Civil 3D 2014 Grading:
http://www.ascented.com/courseware-solutions/autodesk/courseware/autocad-civil-3d/2014/civil-3d-2014...

Michelle Rasmussen made a YouTube about her book. Check it out here:
https://www.youtube.com/watch?v=qNhfQtKFUu4

Dave