AutoCAD Civil 3D

[#1]

C3d 2011 updated to all service packs

39 meg overlot design file

I have had this issue at least 3 times and twice on the same drawing.  I create a surface from corridor and add several polylines and feature line as well as a boundary to the surface.  Randomly it will lose all definition (breaklines and boundary) and i will have to "select similar" (and hope I get everything) and add all of my definition back.

Any ideas why it does this?  It seems to only occur on large files and when my frequency is tight on curve and vertical curves.

[#2]

This may or may not help, but it is generally considered bad practise to edit a corridor surface.  Instead, make a new blank surface, paste in the corridor surface, then add extra data to this new surface.  Make sure you rebuild it whenever the corridor changes.

[#3]

no kidding?...I have never heard that or heard of your workaround for edits. 

I need to ask this communtiy:  Is this a common practice that I have overlooked? 

At our company we have always done the edits (adding breaklines, boundaries and contour) to the corridor surface and only recently has this become a problem.  I will give your advice a shot and see if it helps.  Thank you for the advice.

[#4]

The method Matt mentioned is the one I have used since my second corridor, many moons ago. The corridor surface should remain untouched by the user outside of the Corridor Properties.

[#5]

I have started using the method mentioned above and I am getting the same results (surface loses breaklines, boundary and contour data added to pasted surface). 

Regardless, I will continue to use the "paste" method in future projects.  Perhaps it is a corrupted file.