AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Member
rustee4u
Posts: 5
Registered: ‎01-30-2013
Message 1 of 14 (576 Views)

Grade extension of feature line

576 Views, 13 Replies
06-12-2013 11:26 PM

We are working on a road widenign scheme where one edge of the road is retained as far as possible while  other edge being  widened. I like to design  a retained channel line by extending the cross fall between the existing centre line and the exiting channel line on to the design one.

 

It is possible in civil 3d to extend the gradient between two feature lines at some offset  from reference feature line?

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troma
Posts: 2,520
Registered: ‎05-21-2008
Message 2 of 14 (542 Views)

Re: Grade extension of feature line

06-13-2013 09:03 AM in reply to: rustee4u
Do you mean two feature lines that are roughly parallel, and you want to grade between them?
If so, use a grading. You can grade at a slope to a set distance from one feature line, use that to create a surface and target the surface with a grading from the other feature line.
There are many options in the gradings that you can look into.


Credit where credit is due! Give kudos or accept as solution whenever you can.

Member
rustee4u
Posts: 5
Registered: ‎01-30-2013
Message 3 of 14 (521 Views)

Re: Grade extension of feature line

06-14-2013 02:24 AM in reply to: troma

Thanks for the reply,

Yes the two features lines are roughly parallel at a distance of 7m. I like to create a new feature line at an offset of 10m from the first line and at the same grade as between them.Just to clarify more I have attached the PDF showing  the problem in drawing. The existing grade G shown in the pdf is not constant instead varying. 

 

Thanks

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jmayo
Posts: 2,875
Registered: ‎11-13-2006
Message 4 of 14 (512 Views)

Re: Grade extension of feature line

06-14-2013 06:19 AM in reply to: rustee4u

You can also select the feature line and go to the ribbon. Make sure the Edit Geometry panel is displayed and select the button for Stepped Offset. Provide the horiszontal offset and the %Grade,Slope,ElvDifferenece or elevation you require.

John Mayo, PE
IDSP 2014
Win 7 64, Xeon ES165@3.2Ghz,
64 GB RAM, Quadro K4000 (x2)
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troma
Posts: 2,520
Registered: ‎05-21-2008
Message 5 of 14 (506 Views)

Re: Grade extension of feature line

06-14-2013 06:24 AM in reply to: jmayo
The problem here is "The existing grade G shown in the pdf is not constant".
Say the two feature lines are at the same elevation at one end. Then one goes up and one goes down, then they both do whatever. The desired 10m offset featureline is not found by some known grade or elevation difference that can apply to the whole length. It needs to be at a different grade for every point along the way.


Credit where credit is due! Give kudos or accept as solution whenever you can.

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troma
Posts: 2,520
Registered: ‎05-21-2008
Message 6 of 14 (506 Views)

Re: Grade extension of feature line

06-14-2013 06:29 AM in reply to: rustee4u
I have an idea, but it's quite messy.

Draw a featureline or 3Dpoly from every vertex on the first featureline snapped to perpendicular onto the second featureline. Then do the same from the second back to the first.
Offset the first feature line 10m, convert that to a 2Dpoly. Extend all the perpendicular featurelines or 3Dpolys out to this 10m polyline. Now draw your final featureline by snapping to the endpoints of all the perpendicular featurelines or 3Dpolys.

(I just thought; you could use plain old lines for the perpendicular job too.)


Credit where credit is due! Give kudos or accept as solution whenever you can.

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jmayo
Posts: 2,875
Registered: ‎11-13-2006
Message 7 of 14 (503 Views)

Re: Grade extension of feature line

06-14-2013 06:33 AM in reply to: troma

Yep. Didn't read the first post agian. Doing this manually as you said is the only way I see to extend the existing gradiant.

John Mayo, PE
IDSP 2014
Win 7 64, Xeon ES165@3.2Ghz,
64 GB RAM, Quadro K4000 (x2)
Valued Mentor
fcernst
Posts: 1,104
Registered: ‎01-07-2011
Message 8 of 14 (494 Views)

Re: Grade extension of feature line

06-14-2013 07:24 AM in reply to: rustee4u

This can easily be done with a simple corridor and two generic links, by passing the link slope from the first link to the second link, then extract the corridor feature line.

Fred Ernst, PE
C3D 2015
Ernst Engineering
www.ernstengineering.com
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troma
Posts: 2,520
Registered: ‎05-21-2008
Message 9 of 14 (490 Views)

Re: Grade extension of feature line

06-14-2013 07:34 AM in reply to: fcernst

How do you run a corridor down a featureline?

Maybe...
Create alignment from entity.
Project object to profile view.
Trace the featureline in profile view with a profile.

Few steps involved, but probably less work than my method, depending on the number of vertices involved.  Also has the advantage of being dynamic (to the second featureline at least).


Credit where credit is due! Give kudos or accept as solution whenever you can.

Valued Mentor
fcernst
Posts: 1,104
Registered: ‎01-07-2011
Message 10 of 14 (487 Views)

Re: Grade extension of feature line

06-14-2013 07:40 AM in reply to: troma

You don't need to. They can all just be Targets.

Fred Ernst, PE
C3D 2015
Ernst Engineering
www.ernstengineering.com
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