All the Objects are in different plane

I just imported a file from Autocad and it is in variable elevation . ( Its not in one plane )
I could not push pull those .
Is there any way to bring all the objects to one single plane and instersect with a surface .

Please help me out . People say it can be done in AutoCad but i don’t know it properly …
Please any way to do it in SketchUp

In AutoCAD there is a shipped ‘flatten’ lisp to do it.
In SketchUp there are some similar ‘flatten’ tools - search for plugins/extensions…
@SCF…
Also @Smustard.com …

In SketchUp Pro, to “flatten” without plugins:

Select the top view. Switch your camera to Parallel projection. Export a 2D image to DWG to full scale. Import that.

Anssi

If you install Architect Tools there is a flatten function:
http://extensions.sketchup.com/en/content/architect-tools