15:38 May 18 

And I think this is most likely, i.e. "fond de coupe" is (would be) the bottom of the excavation, aka "arase de terrassement", so we are dealing with the natural in situ materials that have not been excavated ("coupés"), and testing them by rolling to check, presumably, that they do not compress a significant amount if at all. "Fond de fouilles" would be another - better, or at least more customary - way of saying the same thing. OK, figured it out: the first few ghits for "fond de coupe" PLUS "terrassement" are Canadian, so I assume it's québecois for "fond de fouilles".

15:26 May 18 

It PROBABLY matters little to the translation, but I'd love to know more about this "coupe". Is it the ground itself, after levelling? Is it a layer of fill placed on the ground, and constituting the "bottom layer of the formation cross-section" (which could also be the rolled natural ground)? Is it rolled separately, or is it covered with other materials first (prob. depends on total thickness of formation)? Or is "coupe" the largest/smallest fraction of aggregate after screening? Is it the actual formation (or its subbase) or is it a "planche d'essai" .... ? etc.

13:10 May 18 

The "materiaux meubles" are the uncompacted materials that are being tested by the passage of the vibrating roller.

13:07 May 18 

What are "les materiaux meubles"?
Seems some confusion: are we testing the rollers or the rolled?

13:02 May 18 

fond de coupe = excavation face
epreuve de roulement = endurance trial

The excavation machinery must be capable of operating in the terrain, it won't do to have them topple over.