AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Valued Contributor
corboto
Posts: 90
Registered: ‎09-04-2006
Message 1 of 5 (1,141 Views)

Superelevation corridor with ETW design profile

1141 Views, 4 Replies
08-15-2012 08:24 AM

Firstly, I'm a superelevation noob and need some help.  But I've got a highway project for which I'm modeling the corridor but the design profiles given to me are for the right lane top edge (ETW) and not the centerline (crown).  This is an undivided planer roadway with a typical 2% cross-slope.  How can I use that profile for the right edge to run my corridor?  I can't seem to get the corridor to use the super table that is attached to the centerline when I use an offset assembly.  Is an offset assembly the right way to go with this design?  

 

What I've done just to get going is to take that right edge design profile and draw it in my centerline profile view, then lower it 0.24' (which is my 2% normal cross-slope for a 12' lane) and then use that as a centerline profile and let my normal super assembly and table data control the corridor through the supers.  So far that is working--but is there a better way to do this?  Thanks.

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dgordon
Posts: 1,474
Registered: ‎12-14-2006
Message 2 of 5 (1,129 Views)

Re: Superelevation corridor with ETW design profile

08-15-2012 10:45 AM in reply to: corboto

why is the design centerline alignment and profile not available?

 

 

Dan

Civil 3D 2013
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Valued Contributor
corboto
Posts: 90
Registered: ‎09-04-2006
Message 3 of 5 (1,122 Views)

Re: Superelevation corridor with ETW design profile

08-15-2012 11:08 AM in reply to: corboto
Because that's the way highway plans are done here in Arkansas. You're given the high side profile or an edge of pavement profile throughout the job. Everything is then built off of that lane profile.
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dgordon
Posts: 1,474
Registered: ‎12-14-2006
Message 4 of 5 (1,116 Views)

Re: Superelevation corridor with ETW design profile

08-15-2012 12:16 PM in reply to: dgordon

if the side of the roadway is a design profile then it probably already has superelevation built into it, so i'm not sure that a simple 2% to center is going to be accurate.   it should be accurate for the straight sections, but the curved superelevated sections will be flat at some spots and reversed in some spots from positive 2% to negative 2% or greater.

 

 

Dan

Civil 3D 2013
Win 7 Pro x64
Intel Xeon 2.0GHz
12Gb Ram
ATI Firepro 4800
Dell T5500
www.preinnewhof.com
Valued Contributor
corboto
Posts: 90
Registered: ‎09-04-2006
Message 5 of 5 (1,093 Views)

Re: Superelevation corridor with ETW design profile

08-16-2012 12:46 PM in reply to: dgordon

Thanks for the comments.  So far this actually appears to be working, though I have to "trick" C3D a little bit.  The tangents, obviously, can be dealt with and work just fine; it's the curves that require some work.  Here we always pivot out SE curves around the inside of the curve--therefore because of that, curves to the right (pivots inside on the right) are also working just fine.   Let me know if any of this is wrong, but C3D appears to be taking my lowered CL profile, extending the lane up and to the right @ 2% then back across to the left at my 3.7% SE cross-slope.  Thus this produces the correct ETW profile grades in the right hand curves.  You can see this in my attachments.  By the way, my normal section is two 12' lanes with a 2% cross-slope with the right side being the high side.  On the curves to the left I have to "trick" C3D by telling it that left hand curves pivot around the outside of the curve (the high side).  This appears to be giving me the correct right side profile grade.  C3D is taking my CL profile, extending up an to the right @ 2% then back down and to the left at my SE x-slope (which is actually 3.7% in this curve too).  Does this look right?  Am I missing something?  

 

 

It appears that what I'm doing now is working.  But back to my main question: is there anyway to build a SE corridor using an offset assembly with my right lane profile that is provided to me?  I can't get it to work.  

 

Thanks.  

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