When importing pipe networks from a SHP file with the standard Civil 3D functionality, the available options may not be sufficient for a typical pipe network. Common challenges include: Multiple pipe and structure materials Pipe diameters or structure sizes that do not match available parts Missing invert or rim elevation data Missing structures Multiple network types stored within a single shapefile If you have iDAS 12.4 Update 1 or a newer version, you can instead use iDAS