Intersecting surfaces when going around a curve

[Yellow600]

I have posted a few times and it has been really helpful.  I try and figure it out on google or youtube first, but if it takes to long I come here.

So, I have a 4ft ditch with 2:1 slopes shooting up to an existing surface.  When the alignment goes around the curve and the corridor gets generated, the surfaces crosses each other and creates a bad area.  Whats the best way to approach cleaning this corner up?

I'm a former Terramodel user, pretty simple to make it do what you want.  Civil is a bit cumbersome for me.  I'll figure it all out one day!

Thanks!

Jon

[Jay_B]

See this Civil4d Post for one way of handling those Corridor "Bowties".

[Yellow600]

Thanks for the tip. Trying to follow along and I'm lost! I split the region where I needed to and set my daylight to none. My corridor got rebuilt and the bowtie is gone. I'm not sure how to set a boundary and set the corridor extents as the outer boundary. Basically I'm lost after step 1. Sorry.

[Jay_B]

First create a Corridor Surface if you haven't already, then in Corridor Properties > Boundaries tab > Rt. click on the surface name and select "Corridor Extents as Outer Boundary".

Note: depending on your version, you may not see this boundary option listed.

Please include your version & service pack of C3D .

[Yellow600]

Okay got that done. but it does not look like it did much.  In the region i split, I turned off my target surface on the left side, which got rid of the bowtie.  I created a corridor surface and in boundaries changed it to "corridor extents outer boundary".  here is what it looks like now.  It does not look like the corridor extents boundary did anything.

Sorry if i'm frustrating you, just trying to learn so I know the correct way to fix this stuff in the future.

C3D 2014 SP2

[Yellow600]

Here is an attached drawing

[MikeEvansUK]

Unfortunatly the model contains a Dreffed surface which was not included so I cant reproduce problem / test items.

However I have a sudgestion but first do you really need to use the corridor to daylight around the corner where you are getting bow ties?

If the answer is no then I would change the extents of the region "RG - LIMITS - (7)" to extend further in both directions away from the problem zone.

Next, according to my question re daylight you now have two options.

Extract a corridor feature line for the Ditch out or Hinge on the inside curve, create a grading using the same daylight as the corridor. This will fill in the gaps and more importantly without bowties. You can then add this data to the surface model.

If by Corridor is a must then: Do as above then create convert the featureline to a 3d polyline/2Dpolylines and generate an alignment & profile of existing ground.

Add the alignment as a new baseline and generate a new corridor assembly which works from the "Outside in" setting the sampling extents to larger than required and using the ground profile as the design profile and the hinge as the target.

Add new sample sections to try and tie into the corridors main baseline. This is a usefull method and as I have learned sometimes you have to work backwards with corridors (ie from the outside in). Note you may have to clean up the daylight alignment to create as smoother curve / transition as possible.

Which method you choose depends on what you need, I rearly use the latter outside in for this situation opting just to use a grading to clean up the area.

[MikeEvansUK]

I thaught about this last night and there is one aditional option here.

You can just edit the corridor section and delete the subassemblies where they are crossing over. Fiddly and messes up if you adjust the region start/end locations or alignment length.

[Yellow600]

Thanks everyone for your input.  While I may not have used anyone's as a solution I played around with it for a while and this is what I got it to look like now *(See Attachment).  As I continue to advance my autocad skills i'm sure I'll understand your bowtie concepts better.  Thanks!