I think it was Heinlein that had the loonies digging deep trenches, then putting in floor, walls, and ceiling, sealing it up, and pushing the overburden back over the completed tunnel.
A good job for a robot trencher! Too bad we're sending people back first. Putting the same money into teleoperated robots would get more work done, since the robot would not need air, or water, or sanitary facilities, or food, or much radiation shielding. They could operate two or three shifts and "sleep" during lunar night. If we could land a nuke plant there we could fuse the lunar soil into building panels with another remote factory (much harder to to than a digger I think). Then, when people show up, they use the panels to line the trenches and caulk them tight.
Ooh, ooh, I know! Build a Space Shovel!
You still need to know how deep to make the trenches, but there is a cutoff point where it does not matter- imagine being at ground zero when Tycho was made!