Feature line (grading) editing

[DANIEL.FERNANDO.VALENCIA]

Hello everybody,

I have an issue with the limitis of the fill slopes of my platform. It happens that I need to "cut" or "trim" the limits of the fill slopes of the platform when they reach the axis of a little retaining wall. Right now the grading and surface look like I show in the next image (plan view):

Trimming the exterior border of the the slopes is what I need to do, in order to have a something like this:

When I try to trim the lines it shows the following message:

I don't know what to do in order to have those slopes limited by the "retaining wall", which is actually just a simple polyline in the drawing. If anyone can help me, I would be really grateful. Thanks in advance.

[pperales2]

If you know the characteristics of the retaining wall why dont you just grade the retaining wall in, then when you use grading object grade to surface and it should stop at the retaining wall.

Other than that I am not sure what you are trying to accomplish. Can you do a quick sketch of the end product in profile view.

[fcernst]

I prefer to use a Corridor because there are several subassemblies that allow you to override the Daylight offset with a Horizontal Target..

[Neilw_05]

As was mentioned below, you want to stop the fill slope grading before it meets the wall. You would have to split the fill slope grading into 2 parts and stop them some distance before the wall on each end. From there you would add 2 featurelines to close the gaps between the wall and the fill slope gradings. Then add infills to the closed areas

[ChrisRS]

Sticking with the grading object/feature line approach that you are using. I see three possible solutions.

1. Create a closed polyline that traces over the retaining wall and encloses the extraneous grading surface. It does not have to be exact. Apply this as a hide boundary. This is dynamic. You can change the pad elevation and the boundary will (probably) still be correct.
   
2. Add the retaining wall to the existing grade surface. Thís can be done with a closed feature line at the base and a stepped offset for top of wall. This is a dynamic solution.
   
   
   
3.  Do not grade in the vicinity of the retaining wall. Add a feature line to close the gap. You will want to add some elevation points at appropriate point at pre-calculated elevations.
   Then add a grading infill. This is not a dynamic solution.
   
   

Option 1 is the easiest and is dynamic.

Option 2 is 'elegant' and not much harder that option 1. It is dynamic.

I have used Option 3 a lot. It is the hardest and not dynamic. I do not recommend it. 

They all give similar results:

I hope that this helps.

Editorial: 

I often make use of grading objects. They are temperamental and unstable. 

I am trying to learn/adopt feature-line based corridors for site grading. Daniel, I suggest that you consider the doing the same.

Autodesk has some corridor-based site grading demos, but they are basically just curb island grading for large parking lots. Beyond that we seem to be on our own. There are high ranked active participants, like@fcernst, on this board that seem to favor corridor-based site grading. I choose to accept their evaluation.

Note:
I think @Neilw_05 covered some of this while I was composing this post. Thanks, Neil.

[DANIEL.FERNANDO.VALENCIA]

Thank you for your help (this is for all who commented). I have a question. if I do apply the solution 1, the resulting surface is going to be real as I want it (trimmed), or the part I want to trim is just going to be hided? I'm asking this because I need to export the whole surface to revit later.

Again thanks a lot!

[ChrisRS]

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@DANIEL.FERNANDO.VALENCIA wrote:

... if I do apply the solution 1, the resulting surface is going to be real as I want it (trimmed), or the part I want to trim is just going to be hided? ...

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You are very welcome.

I have never used Revit, so this is untested.

My understanding is that the C3D Surface to Revit process starts by exporting the Civil 3D drawing to standard AutoCAD format using EXPORTTOAUTOCAD.

In this AutoCAD format drawing the original C3D surface is represented by 3D poly lines derived from the surface contours as displayed in the C3D drawing.

The answer to your question is 2 part:

1. In the C3D drawing the Hide boundary is a non-destructive break line. If it is deleted, the hidden part of the surface returns.
   In the C3D drawing, the surface is hidden, not trimmed. 
2. The exported AutoCAD format drawing contains nothing about the actual C3D surface. It does contain 3D polylines that are identical to the contours displayed in C3D. These contours are trimmed to the hide boundary in C3D. This resets in trimmed lines, not a trimmed surface, in the AutoCAD format drawing.
   In the AutoCAD format drawing, the surface representation is trimmed, not hidden. 

This is a screen shot of the AutoCAD format drawing. You can see that the 'contours' are actually trimmed. In Option 1 you can also see the grading object feature lines that have been exported. (Freezing or turning off the grading object layer should prevent these lines from being exported.) 

You can see the trimmed contours in this 3D view. The extraneous grading object lines are also visible.You can freeze, or turn off the grading object layer in the AutoCAD format drawing resulting in:

The C3d version of the drawing was included in my original post. You can play around with it.

The exported AutoCAD format drawing is attached to this post.

I am not going to install Revit to test further. That is up to you.

It would be nice if you posted your observations and results.

Good Luck.