So, the wasteland is a horrible and harsh place that wants nothing more than to make your insides something else's insides.
That being said probably one of the more reliable ways to protect yourself in the wasteland if you are so determined to build there, are Tek shields, they (The corrupted) will gnaw on them, along with everything else, but it's the best bet while your turrets of Velonasaurs take care of the invaders.
Problems with the Above, Tek shields seem to suffer an issue in which when beset upon by high numbers of creatures (Most easily replicated with corrupted as they universally hate everything that is YOU) creatures will often out right charge THROUGH the shield, as if it wasn't there. And between that and the Velonasaurs as of 287.123/124 being unable to shoot a barn reliably it's a bad time.
NOW, I'm pretty sure as to WHY this happens, not absolutely, but pretty sure. No matter the number of creatures not ONE can phase through the shield on an OSD, barring that which it allows, IE, non corrupted creatures. The Tek shield blocks anything and everything not allied to whom placed it, in fact, it bounces them back slightly, the shield acts less like a solid object and more like a bouncing region check, anything attempts to move within it's radius is pushed back a foot, like a force region rather than a dome. That is until it gets to be too much and gives up the ghost, the tides of enemies washing over me like the wave of death that they actually are.
The OSD shields and Tek Shield generator that came before clearly function to a similar end but by different means, as such when things get crazy, the OSD dome keeps things out because it doesn't have to do a rigorous a check as the Tek Shield.
As it stands the Tek shield needs to have it's mechanics updated, preferably to that of the OSD shields as otherwise it's purpose is defeated quite swiftly by the would be purple invaders that wish to devour me, and everything else.
A concerned citizen.