how to digitize cross sections from manually created sources (hard copies)

[stgospel]

good day,

we had this a riverbed survey project that are created in 1993, the cross sections of this riverbed are created using manual drafting. We only have the hard copies as a source. is there a way to digitize the cross sections using civil 3d thus creating civil 3d cross section objects??

thanks

[mikesmi]

How many different cross-sections are we talking about?  for example are we looking at a generic setup with some daylighting, or are we looking at very custom or "natural" riverbed where each cross-section is very different.

Either way I think you could just take the existing cross-sections and create custom sub-assemblies.  Depending on the sections, generic or "natural', you may be looking at more or less work.

To get the hardcopies into Civil 3d you can digitize if you have a digitizer, scan/import as pdf/trace with snap, or enter the data manually.

[stgospel]

we are talking a lot.. i think we cannot use the generic sub assembly because all cross sections are "natural' thus every section at every stations are different. If we will use the scanned crossection, how can we make it to a cross section civil 3d object?

[mikesmi]

Ok so depending on how much detail you want in your civil 3d corridor will determine how much work you have.

I've attached some basic screen clips of how to create a subassembly from a traced polyline riverbed.

You'll need to change your connection point (origin point) to match your profile and add some point codes and link codes.  At least a Top code if you need a surface from the corridor.

I don't know what version of Civil 3D you have but this has been available for a few releases, I'm using 2012.

[stgospel]

i dont know about you solution. as i see it, i have to repeat this process a thound times over because i have different section per station. anuways, thanks for the help.

[neilyj666]

If you have the offset and elevation info for each section (and the centreline along which the sections were cut), you could prepare a file for importing points along an alignment

It's not going to be a 5 minute job however you tackle it......

[stgospel]

i think we had that.. what we do is convert it to script and import it to civil 3d. and then we will have a polyline. 

[neilyj666]

Depending on the cross section spacing / level  of detail you will then need to create the longitudinal breaklines to correctly define the TIN or if you are just wanting the cross sections as Civil 3D objects and no other info you could just use the info as is and create a "pseudo" surface which will only be correct at each section, then cut sections across this pseudo surface which should reflect the hard copies. Any other section spacing will give bogus results though.

[ccoles]

Are these HEC-RAS cross-sections? They are not typically perpendicular to the centerline. Do you need them in Civil? You could probably build the HEC-RAS model in HEC-RAS, Digitize the river centerline and cross-sections as polylines, convert them to alignments and section lines, then import your HEC-RAS model on top of it.

[Civil3DReminders_com]

My apologies for digging up this old thread and spamming this post. Feel free to ignore it and/or report it to the moderator for deletion if it offends you and your sensibilities. Google returns it as the first result when searching for "digitize cross sections Civil 3D" and since I don't blog as much as I once do my blog posts have dropped off of the first page of Civil 3D results. So this is just a reminder for me to find this info quickly in the future.

Youtube Video

Blog Post