Earthwork volume gaps

[WScottAllenPE]

I have cross sections cut every 50 feet through my project, with cut and fill areas and volumes using average end area method, as desired by my client.
10+00 Cut area = 11.5 sft Cut vol = 0 cys Fill area = 5.6 sft Fill vol = 0 cys
10+50 Cut area = 12.7 sft Cut vol = 22.4 cys Fill area = 8.2 sft Fill vol = 12.8 cys
TOTAL Cut vol = 22.4 cys Fill vol = 12.8 cys

If I add a new cross section between them to show, for example, a box culvert, it adds that section into the calculations. This is large amounts of fill in over the culvert.
10+00 Cut area = 11.5 sft Cut vol = 0 cys Fill area = 5.6 sft Fill vol = 0 cys
10+25 Cut area = 1.3 sft Cut vol = 5.9 cys Fill area = 22.0 sft Fill vol = 12.8 cys
10+50 Cut area = 12.7 sft Cut vol = 6.5 cys Fill area = 8.2 sft Fill vol = 14.0 cys
TOTAL Cut vol = 12.4 cys Fill vol = 26.8 cys

But, this is not accurate, because the culvert excavation and backfill are paid as different items. I don't want this section to be used for my earthwork volumes, but i want it shown in the cross sections. So, what I need is:
10+00 Cut area = 11.5 sft Cut vol = 0 cys Fill area = 5.6 sft Fill vol = 0 cys
10+25 (no data to be shown)
10+50 Cut area = 12.7 sft Cut vol = 22.4 cys Fill area = 8.2 sft Fill vol = 12.8 cys
TOTAL Cut vol = 22.4 cys Fill vol = 12.8 cys

I have tried to use the gaps in the material list tab, but I get this:
10+00 Cut area = 11.5 sft Cut vol = 0 cys Fill area = 5.6 sft Fill vol = 0 cys
10+25 Cut area = 0 sft Cut vol = 0 cys Fill area = 0 sft Fill vol = 0 cys
10+50 Cut area = 12.7 sft Cut vol = 0 cys Fill area = 8.2 sft Fill vol = 0 cys
TOTAL Cut vol = 0 cys Fill vol = 0 cys

How do I do this?

[Quantum]

I am not going to pretend that I know anything about Civil 3D, but I have used a civil package in the past that was capable of doing earthwork calcs. If you are using the software to generate your volumes, you should create two different tins (if Civil 3D uses this for its 3D geometry and calcs). Create a tin for "Earthwork without new culvert" and a tin for "Earthwork with new culvert". The difference should give you the numbers you need for the culvert excavation. As for the representation of culvert on your cross-section drawing, I would just draw it in using AutoCAD if possible. Then I would put a note saying something like "The volumes in this area do not account for shown culvert.". Also, you could list the excavation volumes if you wish.

Another method could be doing this manually and cutting sections across the culvert. Hope this helps.

[WScottAllenPE]

Quantum, thanks for your comments. I completely understand your approach, and have used that approach. But ...

My real issue is that I don't want to have, or be forced to have, earthwork quantities for an intermediate section. The discussion with a box culvert is only an example, but I have the same problem for other storm sewer crossings, for driveway sections, etc. With driveways, for example, I just show from centerline one direction, and that really messes up what areas and volumes it comes up with.

The correct thing would be for Civil 3D to be able to ignore an intermediate section and allow me to maintain a fifty-foot spacing of the earthwork volumes from sections.

Thanks anyway. Does anyone else have any other ideas?

Scott

[Quantum]

So, to clarify, Civil 3D is generating a cross-section for your utility crossings? The software I used in the past you had the ability to dictate what sections you wanted cut. It should only use the tin you tell it to (i.e. the tin without the culvert) and therefore come up with some accurate numbers. If in doubt, run your average end formula on the 50 ft stations stradling the crossing. However, I still may be misunderstanding you. Hope you get it worked out.

[WScottAllenPE]

Quantum, I myself use to use EaglePoint, but have been on Civil 3D for at least six years now. (I can't even remember when I made the switch.) EaglePoint certainly did have some benefits to how it cut sections, and how easily you could edit them. But, it wasn't dynamic like Civil 3D is from the beginning through the end.

Since you are not familiar with Civil 3D, I'll briefly fill you in on sections.

You start by creating your alignment and your profile. Then you create your cross section assembly that portrays what your roadway section looks like in general.

You create a corridor that is built from your assembly that is projected to follow the alignment horizontally, and your profile vertically. For the outside slope tie-ins, you can tell the corridor to project your slopes to target whatever surface you specify. Whenever you change your targets, you must create a separate region with a separate set of definitions for alignments, profiles, and targets. (Note that this is simplistic. You can create much more complicated sections by targeting offsets for changing lane widths, target profiles for ditch depths, etc.)

Then you specify where you want to create cross sections by specifying the location of your sample lines. Civil 3D will have a section wherever you specify a sample line. I add sample lines for major utility crossings where clearances are important. I also add half sections at driveways.

In order to create your cross sections, Civil 3D will show your corridor section at your sample lines.

Earthwork volumes are defined afterward. You define which surfaces target the top and the bottom of the cut and fill volumes.

All this is nice, and is all dynamic so if you change the profile in an area, everything can be updated without a lot of rework.



However, I don't know how to tell Civil 3D to skip over one section for earthwork calculations. Does the gap feature really work and I'm just using it wrong?

Yes, right now, I am taking the areas, exporting them into an Excel file, calculating the volumes, and inserting them as text back into a table on a sheet. But, this breaks my dynamic link, and I have to do this manually, introducing a weak link for errors.



I have this habit of asking of this forum questions that put Civil 3D to and beyond its limits. The answers I get for my questions are typically "C3D can't do that." But am I really the only person that has this problem? How are the rest of you guys dealing with these issues?

[Quantum]

I have this habit of asking of this forum questions that put Civil 3D to and beyond its limits. The answers I get for my questions are typically "C3D can't do that." But am I really the only person that has this problem? How are the rest of you guys dealing with these issues?

Nothing wrong with pushing the limits of the software. For the price of the software (i.e. C3D), the dynamic stuff should work like a dream. Bugs are bugs though. Fyi, I'm a former EaglePoint user (didn't think there too many of us out there) as well. As good for roadwork as it was, it had its share of quirks. Until then, have you thought about using ACAD's fields and tables? You could put a formula field in in the table that reads the areas on your cross-sections (i.e. closed polylines) and then pumps out the numbers you want. It is very unlikely that if a change is made that the field will read the C3D object(because they're probably not polylines). However, if you made an area using the BPOLY command for the field to read, it would be evident that there was a change and you will have to update the polyline(which may be a pain depending on how much changed). This idea may be more work than it is worth but may be a work around that is acceptable. Hope somebody else has a C3D-centric answer for you. Best of luck.

[cadtag]

could you use a different section line group for your 'special' sections? Seems that if your eartchworks calcs are based on 50' intervals, and you want to ignore atypical conditions that happen within the 50ft increments, that a different SLG on the same baseline alignment would give you sections for the oddballs without impacting the 50' volume calcs.

or am I way off base here?

[WScottAllenPE]

Cadtag,

That is actually a good way around my problem for the earthwork quantities.

However, the drawback for this is that I would not be able to get the sections to order themselves correctly, especially using the plan production tools. That is, my Sample Line Group 1 would display in order 10+00, 10+50, etc. And then I would have SLG 2 after it.

Any idea how one could combine the two? Let me ramble for a minute and see what you think.

I guess one way would be to have a SLG for just the earthwork sections to calculate earthwork and a SLG of all sections just for diplay. But then, I would have to figure out how to add the calculations for the one section SLG to the other section SLG. So, how about having the two SLGs, but instad of skipping over the sample lines that I wanted to hide, I include one, say at 0.001 feet beyond the one in front of it. I could use a style to hide the section view, but show the earthwork, and hide the earthwork qtys for the unwanted sections. If you inserted both plan production sets at the same origin, they would overlay on another in your viewports. Make since?

Show Sections only for SLG 1..........................Show Qty only for SLG 2
10+00...................................10+00..........Ac= 11.5...Vc= 0.......Af= 5.6...Vf = 0
....................Hidden table for 10+00.001....Ac= 11.5...Vc= 0.......Af= 5.6...Vf = 0
10+25
10+50...................................10+050........Ac = 12.7..Vc = 22.4..Af = 8.2..Vf = 12.8
............................................TOTAL ........................Vc = 22.4................Vf = 12.8

So, voila, I show the sections I want (column 1) with their earthwork tables hidden, and I show the earthwork tables I want (column 2) with their sections hidden.

What do you think? Would this work?