Try this.
Nice model, looks good, functional layers...
Comes in to the right scale/units.
The only drawback to the model is that all layers are set to color "white" and each individual object is overridden to be the colors you see, which is backwards to the "proper" way "most" people use Autocad. No biggie since this is easy to fix. Select all - set color ByLayer, then make the layers whatever color you want...
That and it exports everything as polyface meshes rather than solids, but I'm pretty sure M2S.lsp would take care of turning them from meshes to solids.
I like it. Softplan exports pretty decent with good usable file... nice to know I guess.
The grade beams come in as 4 separate objects mitered at the corners, with the slab being a whole other object (making 5 total than make up the slab)
All girters are one object, per wall. All fascias are one object.
Again, not problems... just noting... it seems like conversion problems that used to exist are nearly eliminated these days, the more I see with current technology... seemed like stuff was absolutely horrible 5+ years ago and couldn't work with anything.