Add gradings to define design surface?

[CADNoob96]

Hi there. 

I am wondering if it is possible to add the featurelines produced from gradings to a surface in order to define the surface? 

I have one surface which is produced from 3D Faces from a surveyor - I have titled this Existing Ground. 

I have a second surface which I have titled Design Surface, and I would like to define it with feature lines of my building pad, and the gradings produced from this. I would then like to use a 3rd surface as a comparison surface for volume calculations, I have called this Comparison Surface. 

My issue is that when I add the feature lines to the Design Surface as Standard Breaklines, the surface does not display as I expect. My building pad is a flat pad, yet it shows contours across this flat region. Similarly, the gradings do not display as I expect. I am thinking that the breaklines I am adding are not interacting correctly with the existing triangles from the surveyor. 

Can anyone assist with how I may be able to build this design surface with gradings, featurelines and my existing ground triangles from the surveyor? 

My file is attached, including the gradings, triangles and feature lines at the elevations I would like them to be at. 

Any assistance is greatly appreciated. 

[Valentin_CAD]

@CADNoob96 ,

You will get more feedback from the CIVIL 3D FORUM.

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@CADNoob96 wrote:

I am wondering if it is possible to add the featurelines produced from gradings to a surface in order to define the surface? 

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Something like this:

[CADNoob96]

Hi Emilio,

I am expecting that I would see no contours within the region bounded by the large rectangle feature line (which is my building pad) since all the elevation points of that feature line are the same elevation. I should then see the surface fall away from the building pad at 1% for a distance of 1.3m (this will be on the left hand/north western side), before intersecting a cut batter at 2:1 which intersects the natural ground.

I just tried creating a new Design Surface by adding the existing triangles from the surveyor. Then using the option to automatically create a surface from a grading group, I (automatically) created another surface entirely built from the grading group. I then pasted the grading group surface onto the new Design Surface as an edit and it appears to have achieved what I wanted - the surface matches existing ground where it is outside the extents of cut and fill batters, and it matches the design levels where I have specified those using feature lines.

While this method has worked, I am open to any other suggestions people may have!