Check out some options how pdf files might be converted to skp format.
Unfortunately it appears that PDF documents cannot be imported to Sketchup to produce .skp drawings, except in the Mac version that can import PDF files as raster images. You will need some CAD drawings like DXF or DWG for Sketchup.
A viable alternative would be to convert the graphics from PDF document to some vector graphics like SVG or DX, which you ou can do that in programs like Inkscape, and then import that to SketchUp.
Updated: April 6, 2017
Unfortunately, there is no detailed software record in the database for this conversion.
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