We can just put them up in strategic places that will prevent a 1 turn walk over.
It won't prevent that though. They just need to bring bombers or land artilery, if they bring enough units 1 barricade can be attacked enough so that it is broken and then the tanks can roll though.
It might not be a bad idea to put them in some very strategic spots however note that it will delay not stop a planned out attack and lower our production.