How To: Move elevation data from DXF to ARC
How to read a DXF file with elevation data in ArcInfo?
ARC does not directly support elevation data with DXFARC. Line thickness is supported, however. Set the line thickness to the elevation in AutoCAD, prior to creating the DXF file. When converted, the .ACODE file in INFO has the elevation in the item DXF-THICKNESS. Use RELATE, CALC, or JOINITEM to convert this data.