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View Full Version : How tall a building can be built with todays technology



JHotz
2005-Aug-19, 07:57 PM
The space launch catapult is a popular topic. Launch from a mountain is often part of the equation. I have read that a one-mile tall building is quite possible. So just how tall a launch structure could be built?

publiusr
2005-Aug-19, 08:23 PM
there was a concept for a mile high building.

The Burj Dubai is worth a search. It will surpass that ugly "Freedom Tower" concept.

Petronus already surpassed WTC

Saluki
2005-Aug-19, 08:31 PM
No building is going to aproach the height of a decent-sized mountain. Find a mountain near the equator that has an ocean (or largely-unpopulated area) nearby to the east, and you have your ideal launch site both from a delta V perspective and from a safety perspective.

jfribrg
2005-Aug-19, 08:33 PM
IIRC, Frank Lloyd Wright proposed a 2500 foot building in Chicago, but the idea was scrapped after someone calculated that there would be a severe bottleneck on the elevators. It would take 3 hours or some such for everyone to get to their floors and then 3 more hours at the end of the day for everyone to get back to ground level.

Van Rijn
2005-Aug-19, 09:21 PM
You can get a mile or two up with a passive structure. Buildings are already starting to use active and semi-active stabilization. If you want something tall and thin, you'll need active stabilization to go up a few miles. With advanced materials and active stabilization I've read suggestions that a building could be tens of miles high.

Beyond that you would need something like the space fountain:

http://www.answers.com/topic/space-fountain

which we aren't going to build soon. But in theory, it is possible.

Better have a good transportation system though. As jfribrg mentioned, conventional elevators won't do. You probably would need a system where multiple cars can share a tube, and can shift between tubes - a true vertical transportation system. Turbolifts, anyone?

zebo-the-fat
2005-Aug-19, 09:25 PM
How about this, a 1Km high solar power tower!

http://www.wired.com/news/technology/0,1282,66694,00.html


(That's it, computer going off now, will return after the invasion of Florida, bye for now folks! :D :D )

JHotz
2005-Aug-20, 03:17 AM
No building is going to aproach the height of a decent-sized mountain. Find a mountain near the equator that has an ocean (or largely-unpopulated area) nearby to the east, and you have your ideal launch site both from a delta V perspective and from a safety perspective.The launch structure could be built on a mountain. Maybe Mauna Loa in Hawaii would work.

Sock Munkey
2005-Aug-20, 04:31 AM
Aren't the Hawaiian islands too geologically active for that?

ToSeek
2005-Aug-22, 02:13 PM
IIRC, Frank Lloyd Wright proposed a 2500 foot building in Chicago, but the idea was scrapped after someone calculated that there would be a severe bottleneck on the elevators. It would take 3 hours or some such for everyone to get to their floors and then 3 more hours at the end of the day for everyone to get back to ground level.

That's the real problem: beyond a certain height, so much of a building is taken up with infrastructure that it's no longer cost-effective. I read somewhere that a mile-high building would only be practical if people could be persuaded to wait as long for an elevator as they do for a subway train.

montebianco
2005-Aug-22, 02:44 PM
Petronus already surpassed WTC

Certainly, but one of the WTC buildings was the world's tallest only for a month, as it was quickly eclipsed by the Sears Tower. I've lost track of these things, I don't know if the new building in Taipei is open.

skrap1r0n
2005-Aug-22, 08:17 PM
A buildiing can be as tall as you want, providing you have the money to spend on constructing it. We know enough about load bearing structures and their geometry's to build them as high as we want.

It's just not practical to build them that tall.

Chuck
2005-Aug-22, 10:46 PM
Some levels could have homes, schools, parks, and stores. People would stay near their home levels most of the time and come out of the building only for vacations. There could be bridges to other tall buildings nearby. Rich people on the upper floors would come and go by helicopter.

Will tall hotels superstitiously skip the 666th floor like they skip the 13th floor now?

JHotz
2005-Aug-23, 12:11 AM
Aren't the Hawaiian islands too geologically active for that?I do not think so. There are many observatories there and there equipment is expensive and sensative. In fact the street lights in the town on the big island are special yellow to minimize light pollution for the observatories.

Senor Molinero
2005-Aug-23, 01:03 AM
Dare I say it "The sky's the limit". (insert groans and rimshot here)

The Saint
2005-Aug-23, 11:10 AM
Using 20 ton stone blocks like the pyramid, and an even bigger base area, what's the theoretical absolute maximum height that the ancients could have reached a la Tower of Babel, assuming no manpower, stones and construction problems.

pghnative
2005-Aug-23, 05:31 PM
Will tall hotels superstitiously skip the 666th floor like they skip the 13th floor now?Either that, or perhaps the 616th (http://www.newsoftheweird.com/archive/nw050731.html) floor.


A University of Birmingham (England) professor, working from a third-century Greek text of the New Testament's Book of Revelation, found that the number representing the Antichrist is probably not 666, but 616...




Petronus already surpassed WTC

Certainly, but one of the WTC buildings was the world's tallest only for a month, as it was quickly eclipsed by the Sears Tower. I've lost track of these things, I don't know if the new building in Taipei is open.
Adding to the confusion is how you decide to define "tallest". If you defined it as highest rooftop, then Petronus was tallest. If you included spires, then the Sears Tower was tallest. If you limited the height to that of the highest usable floor, then WTC was tallest. [I don't know how Taipei fits into this list either.] Also, this only includes "buildings" --- I think there are radio towers (some with observation decks partway up) that are taller than all of these.

Saluki
2005-Aug-23, 06:39 PM
No building is going to aproach the height of a decent-sized mountain. Find a mountain near the equator that has an ocean (or largely-unpopulated area) nearby to the east, and you have your ideal launch site both from a delta V perspective and from a safety perspective.The launch structure could be built on a mountain. Maybe Mauna Loa in Hawaii would work.

Yeah, but imagine the cost of lugging all those construction materials up a mountain.

Kesh
2005-Aug-23, 06:42 PM
Aren't the Hawaiian islands too geologically active for that?I do not think so. There are many observatories there and there equipment is expensive and sensative. In fact the street lights in the town on the big island are special yellow to minimize light pollution for the observatories.

Most of the gelogic activity is on the big island of Hawai'i. Which is where the Keck observatory is located, yes. However, it's a short, squat building, which makes it resistant to earthquakes and such in ways that a tall, thin building would not be.

And, frankly, there aren't that many viable, dormant volcanoes/mountains to build on there.

JHotz
2005-Aug-23, 08:07 PM
No building is going to aproach the height of a decent-sized mountain. Find a mountain near the equator that has an ocean (or largely-unpopulated area) nearby to the east, and you have your ideal launch site both from a delta V perspective and from a safety perspective.The launch structure could be built on a mountain. Maybe Mauna Loa in Hawaii would work.

Yeah, but imagine the cost of lugging all those construction materials up a mountain.

Good point

Muana Loa has heavy use roads.

It would depend on how much the launch system was used as the cost could be spread out over all the launches. If there were only a thirty launches then maybe not, but if there were 5 million launches maybe it would be worth it. With the size of the structure we are talking about. The acceleration would probable begin far below the mountain. If part of the accelerator were built first perhaps it could be adapted to transport the building material up the mountain.

aurora
2005-Aug-23, 08:21 PM
Aren't the Hawaiian islands too geologically active for that?I do not think so. There are many observatories there and there equipment is expensive and sensative. In fact the street lights in the town on the big island are special yellow to minimize light pollution for the observatories.

Most of the gelogic activity is on the big island of Hawai'i. Which is where the Keck observatory is located, yes. However, it's a short, squat building, which makes it resistant to earthquakes and such in ways that a tall, thin building would not be.

And, frankly, there aren't that many viable, dormant volcanoes/mountains to build on there.

I think the original post meant to refer to Mauna Kea, which is where the obsrevatories are. mauna kea is probably not extinct, but it is near the end of activity and it may be thousands of years between eruptions.

Mauna Loa, while almost as tall as Mauna Kea, and a much more massive mountain, is still considered active and erupts every 20 years or so.

See here for more:
http://hvo.wr.usgs.gov/

Glom
2005-Aug-24, 07:34 PM
On Extreme Engineering, they covered two attempts to reduce overcrowding in Tokyo. One was the mega city pyramid with skyscrapers suspended in a pyramidal truss over Tokyo Bay. The other way Sky City, a kilometre tall skyscraper.

Here (http://www.discoverychannel.co.uk/extremeengineering/home.shtml)'s the site.

skrap1r0n
2005-Aug-24, 07:54 PM
Some levels could have homes, schools, parks, and stores. People would stay near their home levels most of the time and come out of the building only for vacations. There could be bridges to other tall buildings nearby. Rich people on the upper floors would come and go by helicopter.

Will tall hotels superstitiously skip the 666th floor like they skip the 13th floor now?

It sounds like you are referring to an Ark. It's thought they would me much more efficient to build them down instead of up. Say 100 floors above ground and several hundred below ground.

JHotz
2005-Aug-25, 02:01 AM
It sounds like you are referring to an Ark. It's thought they would me much more efficient to build them down instead of up. Say 100 floors above ground and several hundred below ground.I am partial to underground construction myself. Don’t tall buildings usually have several stories underground?

skrap1r0n
2005-Aug-26, 03:42 PM
It sounds like you are referring to an Ark. It's thought they would me much more efficient to build them down instead of up. Say 100 floors above ground and several hundred below ground.I am partial to underground construction myself. Don?t tall buildings usually have several stories underground?

well yeah, but the Ark concept would then be more like an inverted building with most of the space below ground and only a fraction above ground.

NEOWatcher
2005-Aug-26, 04:17 PM
It sounds like you are referring to an Ark. It's thought they would me much more efficient to build them down instead of up. Say 100 floors above ground and several hundred below ground.I am partial to underground construction myself. Don?t tall buildings usually have several stories underground?

well yeah, but the Ark concept would then be more like an inverted building with most of the space below ground and only a fraction above ground.
I would think there would be a limit there too. Mainly because of the density of the atmosphere.

Saluki
2005-Aug-26, 05:16 PM
It sounds like you are referring to an Ark. It's thought they would me much more efficient to build them down instead of up. Say 100 floors above ground and several hundred below ground.I am partial to underground construction myself. Don?t tall buildings usually have several stories underground?

well yeah, but the Ark concept would then be more like an inverted building with most of the space below ground and only a fraction above ground.
I would think there would be a limit there too. Mainly because of the density of the atmosphere.

I think you would run into engineering problems from the pressure of the soil well before there was a noticable increase in atmospheric pressure.

Now, ventillating this monstrosity would be an interesting problem. The fans to achieve it would be monsterous. An underground building that housed 100,000 people would need roughly 2 million cubic feet per minute of fresh air.

NEOWatcher
2005-Aug-26, 05:42 PM
quote="NEOWatcher"quote="skrap1r0n"quote="JHotz"quote="skrap1r0n"
I think you would run into engineering problems from the pressure of the soil well before there was a noticable increase in atmospheric pressure.

Now, ventillating this monstrosity would be an interesting problem. The fans to achieve it would be monsterous. An underground building that housed 100,000 people would need roughly 2 million cubic feet per minute of fresh air.
I thought I remembered some of the deepest diamond mines having problems with air pressure. What would the air pressure effects be? I tried to find the answer and couldn't, but it would stand to reason, if there is a noticeable differnence between sea level and Denver for instance, that the reverse would be true.
Although I did find a couple of
interesting facts. (http://hypertextbook.com/facts/2003/YefimCavalier.shtml)

Saluki
2005-Aug-26, 06:04 PM
Air pressure has a roughly linear relationship with the height of the air column (Pressure = density x gravitational force x height of air column). Density and gravitational force vary a little, but over the distances we are discussing, it would be a reasonable simplication to call them a constant.

You would need to go at least a mile or more down before air pressure would become a real concern. We are talking about a few hundred stories down, so we are less than 1 mile below the surface.

Sock Munkey
2005-Aug-26, 08:48 PM
Also consider the altitude of the ground you tunnel into. Going 300 meters down into ground with a surface level of 400 meters above sea level means you are still 100 meters above sea level.

JHotz
2005-Aug-26, 10:14 PM
Now, ventillating this monstrosity would be an interesting problem. The fans to achieve it would be monsterous. An underground building that housed 100,000 people would need roughly 2 million cubic feet per minute of fresh air.
In Iran they use a passive system called a Badgir. It is a tower that catches wind and directs it into the structure. There are also cooling towers that spray a mist at their top that cools the air. The cool air being denser falls down the tower and into the structure. The reverse called a chimney could also be used.

fossilnut2
2005-Aug-26, 11:21 PM
"An underground building that housed 100,000 people would need roughly 2 million cubic feet per minute of fresh air."

And 'mole people' to live in it. Where do you folks all live? Myself, I'm partial to sunshine and having Nature around me.

I envision quite an opposite vision for the future. People moving out of urban centers and into more natural settings...whether it be a southwest desert...a northern forest...the Rockies, etc. Geographic location won't be as important as access to information, goods and services. Small and medium sized towns will replace 'cities'. The 'biggest' residential or commercial buildings built a hundred years from now might be no more than a half dozen stories. Large structures might be confined to sporting events, warehouses, medical centers and the like.

JHotz
2005-Aug-27, 12:13 AM
Myself, I'm partial to sunshine and having Nature around me. What sort of nature do you have around you? I have hit 7 deer in the last two years with my car. The mosquitoes are not as bad as those damn crickets. Raccoons keep getting in the dog food and trash. My brother in law had a bear getting into his BBQ grill on the back porch so he threw a string on firecrackers at it and it knocked down the neighbors fence running away so he had to put it back up. As for sunshine I am getting so dark I my wife hardly knows my face not so bad if you are into farmers tans. The heat was bad but nothing compared to the humidity. The grass is a foot high and still too wet to mow. Do not forget our friends West Nile, Rabies, and Lime Disease to name just a few.

I suspect what you really have a taste for is a carefully manicured version of nature. This artificial environment could be duplicated underground. If you are talking about hunting or fishing I a certain you could still do this the same as you do now except there would be more area to do it in as peoples houses are not sprawled everwhere.

I envision quite an opposite vision for the future. People moving out of urban centers and into more natural settings...whether it be a southwest desert...a northern forest...the Rockies, etc. Geographic location won't be as important as access to information, goods and services. Small and medium sized towns will replace 'cities'. The 'biggest' residential or commercial buildings built a hundred years from now might be no more than a half dozen stories. Large structures might be confined to sporting events, warehouses, medical centers and the like.Thank you for sharing you thoughts.

I understand you reasoning but I think you assume other people have the same aversion to urban crowding as you do. I am not sure this is the case.

While information access will facilitate this future there are many things a city offers that information access will have trouble compensating for. Things like a diverse population to interact with. I live in a town of 50,000. Previously I live in LA, Omaha, Hawaii, and Oregon. Larger cities have much to offer that this town does not. Previously I have access to a glass blowing studio, Brazilian Jiu Jitsu studio, large bookstores with coffee shops and live entertainment, local wholesale suppliers of ceramic supplies, night clubs with good live bands, Socrates club, Midwife services, Montessori schools for my kids and much more.
I would say you vision would require a very rapid cheap transportation technology

fossilnut2
2005-Aug-27, 02:09 AM
"I suspect what you really have a taste for is a carefully manicured version of nature. "

I live in the foothills hugging the Canadian Rockies. Hardly manicured at all. Obviously much more serene than where you live. We have moose, elk, mountain sheep, cougars, wolves, whitetail and mule deer and black and grizzy bears. Unlike yourself who have hit 7 deer with your car in the last 2 years...I haven't hit a large animal in 30 years of driving. I don't think the animals are the problem where you live. [-X

True that not everyone doesn't want to live in large cities (otherwise we wouldn't have cities). Large cities, however, grow out of societal economic conditions and those conditions won't be dominant in the future. They aren't even dominant now but many folks (like yourself) are part of a culture where big cities are 'where it's at'. In future 'where it's at' won't be locality specific.

JHotz
2005-Aug-27, 05:37 AM
Unlike yourself who have hit 7 deer with your car in the last 2 years...I haven't hit a large animal in 30 years of driving. I don't think the animals are the problem where you live. That is not the whole story. I haul paper bundles from 1:00 AM to 6:00AM. I travel somewhat remote two lane highways with fields of alfalfa and long windbreaks on either side. My wife has a similar route and between us we drive 5000 miles a month. Between us we have had 15 deer hits in two years. Some caused only minor damage, but my vehicles would be totaled if I had not mounted homemade deer guard on them. The reason the deer hits occur is because the state has allowed the population to grow to attract hunter tourist dollars. It is actually a situation that is less one of nature then one of controlled semi domestic slaughter unless you consider a wheat field natural.
True that not everyone doesn't want to live in large cities (otherwise we wouldn't have cities).Like you I choose not to stay in a large city. Cities have advantages for me but so does living where I do. Living expenses are much lower, low unemployment, less crime, family lives here.
Large cities, however, grow out of societal economic conditions and those conditions won't be dominant in the future.Please elaborate. What are the conditions you speak of?
They aren't even dominant now but many folks (like yourself) are part of a culture where big cities are 'where it's at'. In future 'where it's at' won't be locality specific.I do not feel the way I do because I am part of some culture. I was born in this same town. Went to school here. Went to college in a nearby town and have raised a family here. At times in my life I wanted to do thinks that were not available here so I move where they were available. Things like fighting professionally. I moved to pursue this ambition. I came back several times to reestablish a financial base. I met my wife and started a family. I was unwilling to be away from my family for long periods to continue to pursue my training so I gave it up. If I lived in a big city I would not have had the prohibitive travel.