Pad Grading and Structural Fill

[BradOatOlsenPerformance]

I am working a well pad sites where there is a pad boundary set around future equipment. A feature line is created, following the pad boundary with an elevation generally set 6" above the high point of the EG surface. Side grading from the feature line slope to surface is created. Then an alignment is cut through the well pad. A surface profile is created with shows the existing profile and the new grading. See attached screen shot Within the boundary of the pad (feature line) there is required to have 1.5' of structural fill material. In the real world the structural fill will (cut) the EG surface and also (fill). See attached screen shot. I would like to know how to grade the pad such that I can get an accurate profile and cut/fill quantities of the structural fill material.

[cwr-pae]

Create a surface of the cut area and a surface with your final grade. Create a blank surface, then paste your existing grade surface and the cut area surface (in that order) to create a lower boundary surface of the cut area. Then create a volume surface of the cut surface and existing surface for the volume of cut.  Then create a volume surface between the lower boundary and your final grade for the amount of fill required.

[MMcCall402 · Accepted solution]

I'm not quite sure I understand what you're looking for but this should give you enough pieces to get there.

Offset the current feature line for the pad inward a very small amount and lower it by 1.5'.  Make a surface from this new feature line and the feature line of the pad.  Now you can paste together any of the three surfaces, in any order, to produce composite surfaces to use for profiles and volume calculations.

Examples:

1) A final surface: Paste in the existing surface and then the graded pad surface.

2) Final surface -structural fill: Paste in the made from the two pad feature lines into the surface above.

3) Cut/fill excluding the structural fill volume: Volume surface made using the two surfaces above.

4) Cut/fill including the structural fill volume: Volume surface made from example 1 and existing surface.

5) Structural fill only: Volume surface made from graded pad surface and surface made from the two pad feature lines.

You can profile any of these surfaces individually or the pasted composite surfaces.

[sirjoelsph · Accepted solution]

This sounds like the perfect use of a Dynamic Differential TIN.  There have been many past posts and articles on this subject as well as a good Autodesk University class.  

http://au.autodesk.com/au-online/classes-on-demand/class-catalog/2012/autocad-civil-3d/the-magic-of-...

http://au.autodesk.com/au-online/classes-on-demand/class-catalog/2013/infrastructure-design-suite/ci...

[Joe-Bouza]

https://docplayer.net/57025269-Site-earthwork-using-dynamic-differential-tin-surface.html