Tieing Proposed contours to existing contours

[mjester]

I'm using Civil 3D 09, building a proposed surface by adding polylines as contours. When I created the polylines, I made sure to snap to the existing contours to tie in. My existing surface is x-ref'd and data referenced to my proposed dwg. My problem is that not all of the proposed contours stay tied in to the existing contours when the polylines are added to the surface. Some places double contour lines appear. Is there a command that keeps proposed contours tied in to existing contours?? Any help? Edited by: MJester on Sep 2, 2009 8:51 AM

[Anonymous]

Drape a feature line on the existing grade at the tie in point and make
it part of the proposed surface. Then offset the same line 0.001 to the
outside and make it a border to avoid any odd triangulation.

HTH
JW

[quannguyen]

Settings (weeding factors, supplementing factors & minimize flat area options) might cause the different between the given contours (polyline) and the surface contours. Smoothing options also make the surface contours appear differently. Try to add polylines as break line with small enough mid-ordinante distance might improve the result a little bit.

[MikeEvansUK]

try letting the app do the work (may not work but) use 3 surfaces: eg, prop and final. Model but leave a 5? m gap from tie in to prop. Paste eg into final Delete unwanted triangles now paste prop. Hopefully it will auto complete for you. Fingies crossed : )