Tunnel borers have a sad fate. After being built, at considerable expense, they are generally allowed to fall into disrepair after one or (if they're lucky) two jobs. Meanwhile, nearby strip mines are leaving huge vertical cliffs in mountains, going unused by both beast and man.

To save these giants of the engineering world, bore a few offices!

Digging straight into the rock, a tunnel can be bored. After spraying the walls with any convenient plastic (to prevent water leechage), you simply slide in the building you want, one section at a time. The building would be square, yes, but the outsides of the building would be useful for holding wiring, plumbing, and as air exchange for those down the tunnel. (In fact, it might be necessary; underground facilities, despite the stereotype of cold dark and damp dungeons, are usually TOO good at retaining heat.)

The result would look like a square in a circle. The human-habited spaces would be on the inside of the square; the facilities would be on the outside of the square, but within the circle.

No special cost need be spent on supports, because the building is sitting on the ground. No cost is spent on making the building look good from the outside (except for the outdoor-indoor interface), because what other office buildings have walls made of granite ten meters thick?

The world's largest extant tunnel borers can dig a tunnel large enough to hold a building 3.9 meters square -- a two-story office building with a hallway to one side that can extend as far back into the rock (100m, 200m, more) as you can afford. A tunnel borer of 100m diameter, described as "no special feat" (except for cost) by an engineer friend, could hold a square of 7.97m square within the tube -- that's 3 stories with a central hallway on each side, and two rooms 3.25m wide on each side.

There are only two limits to the depth of these 'boring buildings.' One, the structure of the mountain; the buildings should be no closer than (perhaps, I haven't done the math) 10 meters, to ensure the moutain doesn't collapse on the buildings. Two, there would have to be a mechanism for circulating air, and although the open spaces in the tube would be useful, they would still have to be aided.

The results? Those ugly strip mines are turned into 'office hives', with hundreds (or thousands) of square meters of habitable space reclaimed from what is traditionally considered space. Besides, landscaped offices right in the middle of forest or mountain range look a far sight better.
-- Almafeta, Oct 03 2006

I'm guessing those tunnel boring machines aren't reused because a) they're too expensive to transport; b) they're pretty broken down after one use.

While I kinda like the idea of honeycombing a mountainside, isn't this just another variation on the old "go live [work] in caves"? And in any case, UnaBubba just did this, without the boring.
-- DrCurry, Oct 03 2006


Is this "Engineer friend" of yours really an engineer? 100m diameter sounds like a pretty bloody "special feat" to me. Seriously.

......reading your text carefully reveals you probably meant 10m diameter. Much better. I don't design TBM's but 10m sounds ok.

Oh, go read some literature about the structure of an underground mine. Whilst I could readily see the structures being re-used constructively, I don't know of any with a structure conducive to your proposition.
-- Custardguts, Oct 04 2006



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