We’ve been encountering consistent issues with pipe networks in Civil 3D related to how pipe invert elevations are calculated.
Civil 3D reports pipe invert levels at the center of structures rather than at the inside wall. In construction, contractors set pipes to the inside wall of the manhole using our design data. This mismatch creates problems: either the pipe is installed at the wrong invert level (with the error compounding at each upstream structure), or the contractor adjusts the pipe grade incorrectly to meet the specified IL at the structure wall. This normally depends on the contractor setout methodology.
The attached image demonstrates this clearly — a 30 mm internal drop applied in Civil 3D becomes approximately 86 mm at the structure wall edge.
We need pipe invert elevations to be referenced to the inside structure wall for:
This should be an option or setting within Pipe Networks.
Additionally, structure edge-to-edge pipe lengths are not readily available. It would be extremely helpful if this value could be added to the Toolspace and Properties panels so it can be easily viewed.
These changes would significantly improve construction accuracy and prevent compounding errors in real-world installations.
