Site Grading Comparison

[Chaznsc]

Hello,

If I have a site that I want to grade using two different configurations whats the propoer hierarchy of everything? I am confused as to sites-grading groups-surfaces and how they mesh.

Concept A - Site with FFE of 471

Concept B - Site with FFE of 465

[Neilw_05]

Due to the way C3D utilizes topologies I recommend you prepare each model in separate files. Every featureline must reside in a site and a featureline can only belong to one site, so you'll have to create 2 sets of data. To try to do it all in one drawing would be impractical.

[Neilw_05]

I should mention that you'll want to store the existing terrain surface model in a separate drawing and use data shortcuts to share it between the design drawings.

[Chaznsc]

If I can ask a question - What would happen if I just used two different "finished" surfaces and used volumes based on a comparison between each and the existing surface?

[Neilw_05]

That is typically the way to compute volumes. Did you have some other approach in mind?

[Chaznsc]

If I can clarify, ONE file with THREE surfaces...........

Existing Surface E

Proposed Surface A

Proposed Surface B

I would compare A against E and B against E

[Neilw_05]

You can do it that way, but the surfaces do not have to be in the same file. I would create concepts A and B in separate files, each with it's own finished surface. Then I'd create a 3rd file and use shortcuts to all 3 surfaces for comparing the volumes.

[Jay_B]

If on 2013 or 2014 use the Volumes Dashboard on Analyze Tab of Ribbon and Create a new volume surface using your EG as Base surface and proposed as comparison surface. Volumes Dashboard is also available as a subscription extension add on to 2012.

Note: you may also want to offset the Floor surfaces downward to account for actual excavation limits.

Merely comparing EG to FFE won't include total excavation ie: subgrade excavation etc.

[jmayo-EE]

I agree 100% with separate files. It makes things nicer and cleaner moving forward. Less Fline/grading management.

All surfaces can be D'refed into an analysis file for comparison.

[jmayo-EE]

...and smaller files load and perform faster and better.

[jmayo-EE]

...and each design file can be X'refed into a sheet file and labeld.

🙂

[neilyj666]

and avoids crashing the whole model if a grading misbehaves

However there are circumstances where a quick and dirty single drawing may be more appropriate