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RE: 30,000 foot Skyscraper.. .......!!!!!!

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77 kN/M3 is the density of solid steel.  
The point was that a vertical column under gravity loads only can only stand
so high before it collapses under its own self weight.  By way of
comparison, Mt. Everest is largely solid and unoccupied on the inside (Yeti
notwithstanding) and is about as high as a vertical object made of rock can
get (under Earth gravity...I know Mons Olympus on mars is higher...).
Assuming a solid rock base with a bearing capacity of 10 MPa, even a
pyramid/mountain has its height limits.    

Sounds like an  8 kilometre skyscraper is possible if one covered Everest
with a curtain wall and lived in the space between the existing grade and
the glass.  


-----Original Message-----
From: Michael Donoghue [mailto:cmd(--nospam--at)ibm.net]
Sent: Wednesday, May 12, 1999 06:40
To: seaint(--nospam--at)seaint.org
Subject: Re: 30,000 foot Skyscraper.. .......!!!!!!


Paul,

I recall that the stones in the pyramids were laid to spread the self weight
laterally to the base.  I would assume that a tapered frame (non-vertical
columns in a tapered tower) would distribute the self wt to a some what
tolerable degree.  The structure would have a heck of a basement and
foundation.  BTW, how do you get 77kN/m3?  I would start guessing at maybe
5kN/m3 (~30 #/cf).  Am I doing my math wrong.

My biggest interest is how a structure this size would effect the weather
(rain forrest to the wind ward and desert on the lee).  Why not just develop
the slopes of Mt Everest, someone said our erstwile friends the Chinese
(Then again Everest is in Tibet) were working on a tall building.

Why are we discussing this? I'm done.

cmd

-----Original Message-----
From: Paul Meyer <PMeyer(--nospam--at)HASimons.com>
To: 'seaint(--nospam--at)seaint.org' <seaint(--nospam--at)seaint.org>
Date: Tuesday, May 11, 1999 7:14 PM
Subject: RE: 30,000 foot Skyscraper.. .......!!!!!!


>10 km high (ballpark)
>stress due to self-weight of steel column that high - 77. 0 kN/m3 x 10,000
m
>= 770 MPa.
>So, for a building with 50% net column area at ground floor, (yeah
right...)
>you need a steel yield strength of about 1700 MPa.
>
>We're talking 4340 steel, heat treated and everything, and 50% coverage at
>ground level.
>
>Any other thoughts?  anti-gravity machine?
>
>Subject: Re: 30,000 foot Skyscraper.. .......!!!!!!
>
>
>
>chances are, it may collapse under its own weight.
>
>errm, well it is getting late *yawn*.
>
>Regards,
>  Andrew
>On Mon, 10 May 1999 Rbengrguy(--nospam--at)aol.com wrote:
>> Attention fellow Structural Engineers.
>>
>> This message is just in from the WORLD's Tallest Building website
manager.
>>
>> Maybe you have some thoughts on trying to build a 30,000 foot
skyscraper!!
>
>