Wooden parking platforms?

So it sounds like you're just stacking them together and want to attach them to each other? Pretty much anything will work fine for that. Boards held against each other with a ton or more of force don't slide or shift on their own without any bond, at least in my experience. I have sometimes had trouble with them sliding along the ground when I try to drive up onto them depending on the ground surface, but gluing up blocks wouldn't help with that any. They use loose cribbing to hold up railroad bridges and the like when working on them.

Carpenter's wood glue (preferably waterproof), construction adhesive, epoxy, doweling, screws, nails, bolts, etc. would all work just fine for this application.