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- Newsgroups: alt.folklore.urban
- Path: sparky!uunet!usc!cs.utexas.edu!torn!nott!uotcsi2!revcan!geovision!pt
- From: pt@geovision.gvc.com (Paul Tomblin)
- Subject: Re: Oscillation of skyscrapers
- Message-ID: <Bzq2D7.F0I@geovision.gvc.com>
- Reply-To: pt@geovision.gvc.com
- Organization: Not officially GeoVision Systems Inc., Ottawa, Ontario
- References: <1992Dec18.161420.581@microsoft.com> <1992Dec21.224054.9531@magnus.acs.ohio-state.edu>
- Date: Wed, 23 Dec 1992 17:10:16 GMT
- Lines: 36
-
- PAPAI@kcgl1.eng.ohio-state.edu (Jonathan Papai) writes:
- >ivanra@microsoft.com (Ivan Rancati) ponders:
- >>I heard that high buildings move a bit because
- >>of the wind (1-2 meters in the top).
- >>Does any wise on the net know some detail about
- >>concrete (i.e. Empire State Building) and metal
- >>(i.e. Tour Eiffel)?
-
- TRUE - as a matter of fact, the CN tower (worlds largest free-standing
- building, worlds most over-priced restaurant) in Toronto has a display on
- the ground showing the real-time movement of the top. I think it's more on
- the order of feet than metres, though. Kinda neat how they do the display -
- a laser shining up the hollow core of the building, a sensor arrow (ccd I
- think) on the top.
-
- >The Empire State Bldg. is a steel structure. All skyscrapers
- >have steel as the significant load bearing members.
-
- CN tower is post-tensioned pre-stressed concrete, but then it's a tower, not
- a skyscraper.
-
- >ObUL: Some important buildings in quake prone areas are supported
- >on fat rubber shock absorbers.
- Most, in fact. One of my class-mates (University of Waterloo, Civil
- Engineering 1985) did his masters work with a research company in Japan doing
- active earthquake damping - shoving big wieghts around in the tops of
- buildings to counteract the effects of the building moving.
-
- ObUL: The process of revolving a restaurant causes the cost of the food to
- go up by 20%, and the quality to go down 15%
-
- --
- Paul Tomblin, pt@compass.gvc.com
- (This is not an official opinion/statement of GeoVision Systems Inc.)
- Anybody who doesn't wear a helmet when biking probably _will_ have their head
- examined - by a coroner
-