Interference checks of pipes in 2012

[mthorne]

I have run the interference check on pipes in my pipe network but I am not sure the results are accurate.  I have set the 3D proximity distance to 1.7' in the attached example and Civil 3D found the pipes in interference with each other, but I'm not sure how this distance is calculated.  This distance doesn't appear to be the pipe clearance measured along the perimiter (2.4' in green) or the inside diameter perimiter (1.8' in green) of my structure.  The distances measured directly between the pipes on the inside of the structure doesn't match the interference results either.  I have set the pipe elevations and slopes to the same numbers in this example so I can measure the distance in 2D.  Has anyone else experienced these problems?

[MikeEvansUK]

Are you checking interferances between two different networks or just a single network.

It looks like the latter which will always flag up interferances at every structure with pipe connections and also any crossings.

Otherwise if your checking against two networks then if selected it uses a promximity which is accurate to the dimensions provided.