Corridor issue

[novais]

Hello,

I'm studying some tunnels and some ditches and they all have more than 25% grade. So my problem is when i apply my assembly of a tunnel or a ditch, c3d uses the z from the profile axe and places the normal section vertical when in reality and in the construction site the section is placed perpendicular to the profile.

Can i make an assembly that is placed vertical but does the calculation of the distorcion so all the geometry stays perpendicular to the profile axe?

For example, if my assembly is a plain circle for a tube, it should show all the sections as an ellipse.

Or does c3d permits to draw perpendicular sections? i never saw...

The only work around for the ditch problem was to make a offset with the real distance of the profile axe to bottom of excavation and then start grading it to the top with the same assembly section.

Hope that i explained fairly my problem.

Thanks

Nuno

[mehdi.Autodesk]

Hi Nuno,

can you add some screen shot about your issue, because normaly if you making the sections by sample line from your corridor would be perpendicular to the alignment (by default), and for example if your tunnel cross section shape is circle also it will peresent as circle (divided to line segments) in section view.

 

[tcorey]

If the tunnel is designed as the OP said, where "up" is perpendicular to the slope of the baseline, a section view, where up is perpendicular to the design plane of the world coordinate system, would, on steeper slopes, make a round tunnel look oval.

He is asking how to avoid that. 

I think he/she should consider a programmatic solution that traverses the baseline and creates camera views as it moves along. I don't know how you would get Civil 3D to do this. 

[mehdi.Autodesk]

Hi Gents,
you are right tim i get what she/he need to do in civil 3d
the calculation of corridors (alignment + profile) in civil 3d are plummet (vertical Z axis) base, on the other hand the positive point is aftre creation of corridor and extraction the 3d poly from that the next step can be:
1- Generating the 3D Solid By Sweep or 3D path array commands
2-Project 3d solid object in section View
some how as tim explained the last solution (if the elements array is really complicated) is programing which Autocad is really good foundation for this purpose , i tried it one for TBM precast lining.

[fcernst]

can i make an assembly that is placed vertical but does the calculation of the distorcion so all the geometry stays perpendicular to the profile axe?

You have access to the baseline grade in SAC, so you could make real-time corrections to the vertical dimensions in a subassembly..

[novais]

Hello,

I've attached a simple example from a ditch with multiple high profile inclinations in a plain autocad drawing.

C3D works the corridors and sections always vertical with the World UCS  and inserts the assemblies also vertically, wich in high grade profiles gives big errors in this case to define my excavation bottom and my mid platform. 

For normal project roads, the difference is negible but in cases like this no.

Is SAC the only way (i'm not an SAC expert)? if so:

Can i know the baseline grade and then with math apply the factor of distorcion?

Thanks for all your comments and help.

Note: i'm a 'he' 😄

[sboon]

Back in the early days of Civil3d Peter Funk talked about creating a subassembly to be used on a major bridge project somewhere in Europe (France I believe)  This was back when subassemblies were all written in VBA.  Apparently this particular sub would draw a polyline at each section representing the concrete deck and girder, perpendicular to the alignment and the design profile.  The drawing of those polylines was then used to build the formwork for the precast segments of the structure.

Theoretically you could create something along the same lines using .NET  There will be several problems though - the output would not be a normal corridor, and the tools used for editing corridors would not work.  You might be able to use the polylines to create a surface manually.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[fcernst]

..Can i know the baseline grade and then with math apply the factor of distorcion?

Yes

[novais]

Ok, i'm reduced to the SAC option, in trying to create a assembly that really recreates what that's suposed to do...

I think that this issue is a major flaw in the way that C3D delivers all the output, since it's erroneous information, from (in this example) datum levels for site implemention to volumes reports. And applies basically to everything that evolves grades (in my case) higher than 15%.