Daylight Cut and Fill

[tdavisNXMWJ]

I'm having an issue with civil 3D not accounting for the fill under my daylight and above my subgrade. I have a typical section where the subgrade extends a foot past my top section. I have a datum surface that's being compared to my existing ground to create my volume surface and provide cut and fill analysis. I have the datum using the bottom links as the overhand correction. I'm just not sure how to get cad to recognize that it needs to adjust the fill on the top of the subgrade and below the daylight. Daylight is set to target existing ground. The top subassembly is a basic lane and the bottom is shape trapezoidal. (this is for a sidewalk)

[ecfernandez · Accepted solution]

Hi @tdavisNXMWJ, welcome to the Autodesk Civil 3D forums. Regarding your question, the answer is that Civil 3D cannot do what you are trying to achieve in the way you want to do it. To solve your problem, you can follow any of these two approaches.

1. Create a subassembly to fill the portion you are missing (see image). You can use a subassembly from polyline, a custom subassembly, or a LinkMulti subassembly for that purpose.

Subassembly from polyline

LinkMulti Subassembly

Then, compute your materials again. When doing so, add the new material of the two subassemblies to your main fill material.

2. Create a separate surface on top of your subgrade, one per side. and create the top surface of your corridor.

Then, compute your materials for the left and right sides separately (ideally). Use the top surface of your corridor and the top surface of your subgrade layer as the comparison surfaces.

Any of those steps should help you get the quantities of that missing portion. If you have further questions, post them.

I hope this helps. Best regards!

[lim.wendy]

hi Taylor,

Welcome to the Civil 3D forum! Did you get a chance to look at Camilo's suggestions?

If you still need help, please let us know.

If they helped solve your issue, consider hitting the "Accept Solution" button. This helps others searching for similar problems find the answer quicker. It also lets our community know which topics are resolved and which still need attention. Plus, it's a great way to show appreciation to the person who helped you!

[chriscowgill7373]

I think that @ecfernandez suggestion is probably your best option.  Civil 3d's fill and cut calculations are for subgrade numbers, what undisturbed earth needs to be removed to place the proposed material, or what subgrade material needs to be brought in to get to your proposed material.  Because your triangles are above a proposed material, whatever goes there, would have to be proposed material as well, or "cut" out to place your subbase.  Even if in real life, the material can be native, it still has to be removed, or placed in a separate action from the "mass" grading materials.