Storage calculations and grading tools

[Anonymous]

I built a containment dike using the grading functions in Autocad Civil 3D. I set up the feature lines at the top toes of the embankment and graded nicely down to the original dtm. I want to use user defined contour to get the interior storage from the original dtm up to a selected elevation within the containment dike. The containment dike forms an enclosed area. I know I could use infill and add a false bottom to the embankment surface (triangulation from bottom toe of embankment across to opposite embankment) but I want to check storage from original ground dtm.

Is there a workaround method to do this without creating infill? I know I need to get down to two surfaces to get a calculation.

[troma]

Make a new surface. Paste in the original ground surface. Then add the new data (featurelines) to build the dike on top of the original surface. Now you have one surface showing your final condition.

[Anonymous]

Then there is no need in creating a surface from the embankment?

Just add the feature lines to the original dtm in a blank surface?

[troma]

Two issues here:
1. if you did it the way I just said you will have to delete data from that area as well as adding the new data. Sorry I left that out.
2. If you make a surface with a hole in it and paste it in you will end up with a surface with a hole in it! i.e. no data in the middle.

So you have options.
1. Do as I said before and manually delete data as necessary (messy).
2. Build two surfaces of your dike (e.g. north and south parts) and paste them both onto the copy of OG. (I think this is best.)
3. Build one surface of your dike. Paste it onto copy of OG. Make another copy of OG and give it a border to match the inside bottom of slope of the dike and paste that in on top to get your composit.

[fcernst]

I know I could use infill and add a false bottom to the embankment surface (triangulation from bottom toe of embankment across to opposite embankment) but I want to check storage from original ground dtm.

Just a quick way:

Get the volume of your containment surface level using the infill like you say.

Then do a volume surface calc between your infill bottom and EG. Then add that bit of fill  and subtract that bit of cut to your overall containment level volume.

Done.

[Joe-Bouza]

If I understand correctly you only graded the berm of the dike and the interior bottom is original ground?

I might make a new surface an paste OG into then the berm, now you can compute from a OG to a user contour (I think)

[Anonymous]

Thank you for all the comments.

I thought about weedeing out all the survey points from within the embankment outside bottom toes and leaving a blank spot for my embankment to reside.

I also need to make a surface of the embankment at some time to calculate the volume of fill.

Wish there was an easier way to merge the two surfaces to create my depression for storage calc.

Have a good day everyone.

[fcernst]

Don't do that...bad practice..

If your inside toe is all Daylighted nicely down to EG like I think you are saying, use that Daylight as a Non-Destructive Boundary for EG and paste the containment berm and this 'EG bottom" together,  like Joe has said.

[troma]

Well I'm a little slow...just realised you don't need the OG (EG) outside the berm at all, it's irrelevant, right?
I think Fred has explained the method pretty well here.

[Anonymous]

Yes, the embankment slopes to daylight on both slopes.

I thought about doing what you suggest (use inside bottom toe @ daylight) to create a border to cut out this portion of EG. You could add this existing bottom to the embankment surface to create one surface?

Thanks.

[troma]

Yes

[Anonymous]

I'll try to get the two surfaces into one.

Creating a false bottom using infill just seemed easier for me due to my lack of knowledge.

Not quite sure how to pull off the two into one trick. Do I create the embankment surface, then cut the boundary on the inside @ daylight under the embankment surface?

Bear with me. I'm new to this software.

[troma]

Yes, you're on the right track.
What do you have at the bottom of slope? A feature line?
If so, you can copy it and explode the copy a couple of times. Personally, I would then convert it to a 2D polyline. (Joe will point out the need to weed it too. Featurelines created from gradings can have loads of vertices near each other, weeding removes some of them.)
So then you make a new surface, paste in the EG, then add that polyline as an Outer, Non-destructive boundary.
Then paste that surface into your berm surface (or a copy of it, depending on your needs.)

[Anonymous]

Yes, the daylight line at the inside bottom of the pond is a feature slope.

I'll give it the old college try.

Thank you.