Habitation Domes

[Allan]

Hello again,

If I could ask a question of the structural and math guys this time.

If a mile high dome were to be built on Earth with the desire to cover as much of a city as possible how wide could it be before it is structurally unsound? Is it feasable in our atmosphere that a 1 mile high dome could cover 10 miles, 20 miles, 30 miles, or more? Or is the circumference of the 1 mile dome going to limit it to a two mile diameter?

I've been reading and found one site which suggested that a 1 mile dome could be used to cover all off Manhattan Island and NY City? If memory serves Manhattan Island is 15 miles long and maybe half as wide.

My thinking is a dome comprised of octaganal sections assembled to fit. For my purposes (fiction) materials aren't really a factor since I'm not planning to go too much into detail (though carbon based beams are the front runner in my mind).

 

[jedidia]

The atmosphere doesn't have much to do with it, until you want to raise or lower pressure inside the dome. It's good old gravity that's your major concern, i.e. the weight of the structure...

If you have lower pressure outside that inside (like you'd have for example on Mars, where you also have lower gravity), that would be an advantage, since the pressure from the inside can help you stabilize the structure from within.

But one mile high sounds a lot too big for pretty much anywhere... As for the area covered, you'll want to construct it as a geosphere in any case, that's the most solid for domes. If you don't want to make it spherical, you might as well put some pillars underneath, but still, one mile is utter insanity.

 

[Spike Spiegel]

Here's an example from my area of a glass dome structure:

[ame="http://en.wikipedia.org/wiki/Mitchell_Park_Horticultural_Conservatory"]Mitchell Park Horticultural Conservatory - Wikipedia, the free encyclopedia[/ame]

Maybe it will give you some ideas, though it seems these domes may have been designed for height rather than ground area.

 

[T.Neo]

Yeah, higher pressure inside helps... in some cases, it can actually support the dome. This usefully ties in with cities producing local heat islands...

Buckminister Fuller came up with the Cloud Nine tensegrity sphere; a gigantic geodesic sphere, a mile across, suspending cities. Due to the surface area to volume ratio, the sphere could float and suspend the mass of a settlement if the air inside was only a degree warmer.

Crazy stuff, but captivatingly interesting nontheless. :thumbup:

 

[Pyromaniac605]

All I can really say in the subject is that domes are better suited structurally to pressure at the top.

That is why the Collosseum (I screwed that spelling) in Rome has arches.
Arches and domes are most suited to pressure or force from the topmost point where the force is spread evenly around the structure making it less prone to collapse.

Darren

PS: Don't quote me on that, I'm no Physicist.

 

[OrbiterSpore]

well, the concept is an thing we have in orbiter, the "glass modules" that are observation points to put near other UCGO modules. possible idea, we could add some to ISS!