AutoCAD Civil 3D

[#1]

I have several TB of Lidar LAS data for a very large watershed, so I can only process the smaller catchments without exceeding my computing capacity. However, I would like to build a single breakline file for the all the streams and ditches and apply those breaklines to every instance of surface that I build.

My first attempt has been to draw feature lines with elevation values, and that works fine within a single drawing. But when I try to export the drawing to LandXML and import it in another drawing, I get the surface, but there are no Line Features. It just drops out.

Am I overlooking something as I export the features? Does anyone know of a better approach to the problem?

BTW, I'm working with Civil 3D 2011.

[#2]

It seems to me you would be better off keeping the breaklines in a single dwg and creating a mosaic of data clip boundaries. Using these boundaries you would create a mosaic of surfaces that cover the site. These surfaces would then be data referenced as needed to perform analyses or to display the surfaces in your maps. To reduce processing and resource requirements you would set the display of each surface tile to boundary only in the master file.

I'm not aware of any issues that you might encounter when using data shortcuts to surfaces with data clip boundaries. Hopefully others with more experience in that regard will offer advice.

[#3]

I think wblock and insert are the best way to move feature lines between dwg files. I also think this is Autodesk Best Practice.

John