Alignment Cross Over TIN Issues

[Anonymous]

Hi all

I am new to C3D and new to the forums so I apologize if this question has been asked before, I could not find a solution when I searched.

I have a single alignment that loops over itself. I have created a corridor model and a surface of the corridor. I am struggling to create a smooth surface where the alignment crosses over itself. The triangulation goes from the surface of the underneath part of the road to the top portion. How do I solve the triangulation to create one smooth continuous surface?

At this stage of the concept I am not modelling anything other than the corridor and surface, so I am not tying into existing ground. 

I am using Civil3D 2020 on windows 10

Thanks in advance for your help 

[jroot]

If you have your Corridor as just one Region you will need to make a "gap" where the alignment crosses itself.  Break your Region so there is a gap from about 2+180 to 2+220.

[tcorey]

Civil 3D does not allow single surfaces to do what you're asking. You can't have vertical faces and you can't one part of a surface above another part. That's why Civil 3D can't do a tunnel. in one piece.

You could Extract Corridor Solids to make a single piece 3d model of the road, or do as @jroot suggested and create a gap.

[Anonymous]

Thank you both for your quick replies. @tcorey @jroot 

Seems to be a limitation with the software then

[Apex-Solutions]

you cannot have a Alignment loop over itself.  You can however have the start and the end of alignments meet at the same point although that is not the best idea.

What you need to do is the following:

• Split the alignment into two portions (two separate alignment)
• Create the first corridor and target to base surface.
• Create a corridor surface of the first corridor.
• Create a Combined surface which includes the Base surface and the first Corridor surface
• Create the second corridor and target the combined surface.

You will end up with Alignment 2 crossing over Alignment 1,  after that you are able to create a intersection.  You will however need to take care of the grades at the end of the first corridor and the start of the second corridor to ensure they match.

[Jeew-m]

Hi,

By default you cannot have two elevations for one coordinate in Civil 3D inside a surface.

But I can suggest you this.

• Create two separate corridors to your alignment.  Say Corridor 1 and Corridor 2.
• Corridor 1 will end up somewhere 2+000 (before the alignment crosses it self). Create corridor surface. Say surface 1
• Corridor 2 will start where corridor 1 ends and goes until the end of alignment. Create corridor surface. Say it is Surface 2
• Now when you sample sources to section views (or sample lines) use both surfaces.
• Then they will be viewed properly in section view.
• However you cannot create one smooth surface even by this method.

Thanks