I think it's probably a combo of earthquake and CSEI. Green Lantern was designed for an extremely high seismic area and wasn't even that beefy. I'm guessing they had to really up the sizing due to CSEI's standards.
This is AWESOME detailed picture ! ThanksAh, now that it’s complete it’s a lot clearer what the support structure is.
Appears to simply be a beefier version of Kirnu’s supports, probably for CSEI. I color coded support beams that I found to be similar between the two for reference.
The mine train is also open. I shall dig up a pov later if I can find it again