AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Distinguished Contributor
C3D_RickGraham
Posts: 975
Registered: ‎09-06-2006
Message 1 of 15 (626 Views)

Residential Lot grading

626 Views, 14 Replies
07-21-2008 11:53 AM
Hi all,

I'm looking for ideas on how you would approach this situation that I am in. I'm doing a medium size subdivision (130 lots). I've run my corridor out to the ROW and made a Surface from that. Now I have to do lot grading (yes the engineer wants this - I think its stupid since we're just designing to a maximum footprint and it WILL change when the developer starts placing houses on the lots). But anyways, I have 3 scenarios:

A. Level Land - no basement (Rancher-style house)
B. Walkout with full basement exposed at back of house
C. Walkout with only Basement patio exposed and then shoots back up to grade.

So with those scenarios, here is my workflow:

1. I know what the elevation is at the ROW. From the ROW and center of driveway)I go 5% up to house pad (All driveways are constant 20' long)
2. The Basement level is -7.5' from original elevation.
3. I draw a feature line around the footprint and set elevations.
4. I use FL offset and offset by .01 to show the basement. I set that elevation.
5. I add these FL as Brealines in my surface. It draws the countours.

Only 129 more to go.... It iis my REAL wish that this whole scenario could be tied together with the corridor so that if the road changes, the pads to too. Or if this is too much of a wish then I would like to see a GROUPING of some sortfor the 2 FL's. If the pad elevation changes, the basement will automatically adjust.

I've played with Grading objects a bit and after 4 FE recoveries, I gave up on that! :smileyhappy:

Anyone have any other methods, recommendations, etc.?

Thanks,

Rick
Thanks,
Rick
coauthor Mastering Civil 3D 2012
I blog at http://simplycivil3d.wordpress.com
Distinguished Contributor
haroldpei1218
Posts: 141
Registered: ‎01-15-2008
Message 2 of 15 (626 Views)

Re: Residential Lot grading

07-21-2008 01:15 PM in reply to: C3D_RickGraham
It can be tied together if you're using 2009. If not, well...
Distinguished Contributor
bigblittlerent
Posts: 260
Registered: ‎03-26-2008
Message 3 of 15 (626 Views)

Re: Residential Lot grading

07-21-2008 04:13 PM in reply to: C3D_RickGraham
Many ways to skin a cat...here is a thought:

1) Draw 3D polylines representing your 3 scenarios. Elevations do not matter at this point.
2) Create a feature line of your ROW.
3) Create temporary surface: Stepped offset of ROW feature line 5% for 30'
3) Having never seen your alignments...In some manner draw your twenty foot driveways.
4) Create feature lines from objects (driveways) and assign elevations from your temporary surface
5) move, copy rotate your scenarios to the ends of your driveways (they should pick up elevations from feature lines)


And yes, 09 does make this very easy.
Distinguished Contributor
bigblittlerent
Posts: 260
Registered: ‎03-26-2008
Message 4 of 15 (626 Views)

Re: Residential Lot grading

07-21-2008 04:16 PM in reply to: C3D_RickGraham
or take scenario driveway and all and snap it to your ROW feature line??
Distinguished Contributor
C3D_RickGraham
Posts: 975
Registered: ‎09-06-2006
Message 5 of 15 (627 Views)

Re: Residential Lot grading

07-22-2008 03:46 AM in reply to: C3D_RickGraham
Thanks for the VERY informative response. Yes, I'm sure it can be done in 09 but I haven't wrapped my brain around a good automated process.

Rick
Thanks,
Rick
coauthor Mastering Civil 3D 2012
I blog at http://simplycivil3d.wordpress.com
Distinguished Contributor
C3D_RickGraham
Posts: 975
Registered: ‎09-06-2006
Message 6 of 15 (628 Views)

Re: Residential Lot grading

07-22-2008 03:47 AM in reply to: C3D_RickGraham
Thanks for the responses. I'll have to give that a try. THANK YOU for your suggestion.

Rick
Thanks,
Rick
coauthor Mastering Civil 3D 2012
I blog at http://simplycivil3d.wordpress.com
Valued Contributor
spatzengr
Posts: 66
Registered: ‎03-20-2006
Message 7 of 15 (628 Views)

Re: Residential Lot grading

07-22-2008 04:22 AM in reply to: C3D_RickGraham
We build the 3 FL scenarios off to the side of the drawing and make 3 groups. We copy the groups around for each house by a base point off the middle of the driveway connecting to the corridor FLs at that point and editing the two sides of the driveway to tie into the corridor FLs.

I would suggest making sure your cut\fill for the entire site is close to balance using the sub-assembly and steps available under the following AU course (http://au.autodesk.com/sessions/detail/1248/). You need to login with a subscription account to get the goods. Once that is done and cut\fill confirmed to be close move onto the detailed lot grading with the FL groups of the 3 scenarios.

On your next project include those FL groups in a block with the 2D house. As you are placing the 2D house on each lot you can be placing the FLs for the grading (2 in one).

That said, I don't know of any method (even in 2009) that will make your detailed lot grading FLs dynamic with the corridor model. With 2009, I guess you could try doing your detailed lot grading with Grading Objects and it would be dynamic with the corridor but good luck. I don't think Grading Objects will give you the flexibility you need to get the job done for detailed lot grading OR are stable enough to do that kind of detailed warping needed.

mspatz, P.E.
Distinguished Contributor
bigblittlerent
Posts: 260
Registered: ‎03-26-2008
Message 8 of 15 (628 Views)

Re: Residential Lot grading

07-22-2008 12:10 PM in reply to: C3D_RickGraham
I don't think that you would suggest it if there was any sort of issue. Have you noticed any issues having FLs assigned to a site while nested in a block?

Also, It IS possible for lot grading to be dynamically linked to corridor in 09. It can be accomplished by using the create dynamic feature line from corridor.
Valued Contributor
spatzengr
Posts: 66
Registered: ‎03-20-2006
Message 9 of 15 (628 Views)

Re: Residential Lot grading

07-22-2008 03:58 PM in reply to: C3D_RickGraham
FL blocks\groups:

We have not experienced issues yet, but have only used groups with FLs so far in C3D. We have not done the block thing yet. We bring both of these techniques from LDT were we have done both with 3D polylines for years. Worse case, you can just use 3D polylines in C3D as well for the nested blocks if you experience issues with FLs, nested blocks, and Sites in C3D.


Dynamic FLs off the Corridor:

Yes, you can create dynamic FLs off the corridor that follow the point codes but you lose the dynamics when you build off of that FL. It is not like the building footprint will raise and lower holding the driveway FL slope as the corridor moves and goes up \ down. Maybe the next, or next, or next version! :smileyhappy:

mspatz, P.E.
Distinguished Contributor
haroldpei1218
Posts: 141
Registered: ‎01-15-2008
Message 10 of 15 (628 Views)

Re: Residential Lot grading

07-22-2008 06:38 PM in reply to: C3D_RickGraham
Actually, it will hold the footprint's elevation when you raise or lower the corridor IF you base the footprint off of the feature line from the corridor. Which would be the whole point of it being dynamic.
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