Grading between two surfaces

[Anonymous]

Hello, 

I am currently working on a project where we need to remove all the soil above the rock, and refill it with material.  

I need to evaluate the volume of the displaced soil with a 2:1 slope between the rock and the soil in place (both are surfaces with varying elevations throughout).  I only know how to grade between a flat feature line and a surface, and I can't seem to be able to grade between these two surfaces.

Furthermore, I need to evaluate the volume of backfill, between the rock surface and a set elevation.  I'm not really sure how to proceed, since my feature line isn't predetermined, it is dependant on a 2:1 slope.

The only thing I can see would be to grade between the rock and a set elevation lower than the natural ground, then another grade between said elevation and the natural ground elevation.  However, I'm not even sure this is possible, and it would be time-consuming.

Any help would be appreciated!

J. Tremblay, T. P.

[wfberry]

First things first, I think C3D 2017 gives you the best option.  Good information allows better answers.  So let's start with your version.

Bill

[Anonymous]

I have Civil 3D 2014

[ITandCADguy]

Just enough information to get you thinking (I don't have C3D in front of me right now).

Start at the bottom.

I assume you have a surface for the Rock and another surface for the soil.

Create a feature line for the bottom of the hole, and set it's elevation to be that of the rock.

Next,  Grade to Daylight, targeting the soil surface.  That will give you a feature line defining the boundary of the 2:1 slope.

If no one else jumps in, I'll see if I can provide more detail later.

[fcernst]

• Create a grading and new surface RockEx from EG down to Rock at 2:1
• Create a copy of Rock >> Rock2
• Use the grading Daylight boundary as an outer boundary for Rock2
• Paste Rock2 into RockEx
• Compute volume EG vs RockEx

q

[Anonymous]

I have a similar situation. Where I have an existing surface and a finished grade surface but cannot figure out how to create a transition from FG to EG with only a positive slope. Daylight always goes shortest route. Picture shows the case on right side where daylight would go negative instead of positive.

[Anonymous]

Thank you to everybody who took the time to help me with this problem.  I was able to calculate the volumes I needed.  

I used a 3dPolyline as a feature line and graded to the upper surface, then did a volume check between the lower and upper surfaces, adding these volumes to get the total volume.  (Instead of infilling the grading)

I was also able to calculate the fill volume to a certain elevation with the same steps.

Thank you again!

Jennifer Tremblay, T. P.

[fcernst]

Not sure what you did (adding volumes)?

In Civil 3D you create a Volume surface. If you just created boundaries around Rock and EG,  the volume for the 2:1 excavation would be incorrect, because the volume calculation would not include the 2:1 slopes. It would just cover the area covered by the smaller surface (Rock), between Rock and EG.

[Joe-Bouza]

I'll assume when you target Fg you are gradinfrom someplace else.

I would suggest creating a composite FG-E.G. and target the composite