Honestly fixing the mines alone was good enough. If you mean you don't know how as in you don't have ideas then I can help:
Make the floor of this building thicker:
Combine these 3 into one and put a second entrance within, similar to the S1 industrial base:
Push this back a bit and maybe add a counter or something so explosives don't go straight through:
Aside from that, making the windows on the following buildings unbreakable would increase their basing potential (I think this can be done by server owners on the server? I don't know,):
Also did you do this?
steamcommunity.com/app/1840/discussions/0/626329821171018383/