Civil 3D - Issue:  Pipe Networks and Missing FG Corridor Surfaces

Kevin Breslin

Leo Lavayen | Applications Expert


In some cases within Autodesk Civil 3D Pipe Network loses it's assigned Reference Surface from the Corridor.  In some cases, issues are obvious as the Rim elevation is lowered in profile views, or the labels appear as a “???” for the elevations.


If further inspected, the Panorama window Structures or Pipes tab the Reference Surface column will be empty.


From the object’s Structure or Pipe properties dialog box, the Reference Surface cell would appear empty or as in the example below, may contain random numerical values.



In the Corridor Properties, the Corridor Surface will be unchecked.  The default behavior is that Civil 3D should re-set the corridor surface once the box is re-checked, elevations should immediately adjust, but it doesn’t always happen.



In the cases where the surface has forgotten the Reference Surface, it must be re-assigned.  To both the Pipes and Structures.  I have only seen this in a few cases.

  • First, within the Corridor Properties, make sure the Corridor surface is being created.


  • Next, set the Reference Surface to the Pipes & Structures, from Panorama or Properties


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