Thought Experiment of the Day
Imagine a WTC tower, 110 stories, 1360 feet tall. The ground floor is a 50 high foot lobby.
You blow out all the columns of the lobby-- perfectly-- so that the top of the tower doesn't tip at all but crashes 50 feet straight down.
Question-- what happens when the 2nd floor reaches the ground?
A) Will the tower undergo a reverse pancake collapse, where the 2nd floor crumbles, then the third, then the fourth, etc?
B) Will the tower under go a partial collapse that peters out after a few floors?
C) Will the tower land on the second floor and stop collapsing?
If you say A, how long do you think it would take for the tower to undergo complete collapse? Much longer than free-fall, or essentially free-fall time?
You blow out all the columns of the lobby-- perfectly-- so that the top of the tower doesn't tip at all but crashes 50 feet straight down.
Question-- what happens when the 2nd floor reaches the ground?
A) Will the tower undergo a reverse pancake collapse, where the 2nd floor crumbles, then the third, then the fourth, etc?
B) Will the tower under go a partial collapse that peters out after a few floors?
C) Will the tower land on the second floor and stop collapsing?
If you say A, how long do you think it would take for the tower to undergo complete collapse? Much longer than free-fall, or essentially free-fall time?
posted by spooked at 8:38 PM
5 Comments:
Marrion Awarded Fellow
Date: 12/01/2006
Chris Marrion, PE (Arup Fire NY) was recently nominated to the position of Fellow within the Society of Fire Protection Engineers (SFPE).
Chris leads ArupFire's New York office and is a fire engineer/code consultant. He received this award along with 8 other members of SFPE at the Annual Awards Ceremony.
Over the last several years Chris has been very involved with SFPE including his work on various committees including:
SFPE/ICC's Code Authority’s Guide to Performance Based Design, Steering Committee
SFPE's Design Basis Fires Guide, Chairperson
SFPE's Engineering Guide to Performance Based Design/Analysis of Buildings, 1st and 2nd Editions, Steering Committe
SFPE/NIST-National R&D Roadmap for Fire Safety Design And Retrofit of Structures Workshop – Steering Committee
SFPE Reference Manual for the Professional Engineer’s (PE) Examination in Fire Protection Engineering, co-author
SFPE also put Chris's name forward to serve as one of the fire engineers on the FEMA/ASCE WTC Building Performance Assessment Team where he co-authored the WTC 1, WTC 2 and WTC 7 Chapters in the FEMA: World Trade Center Building Performance Study Report.
read that last sentence carefully, what was Arup's role??
Obviously, Spooked, it would disappear into the basement and on into the bedrock, which would be pulverized to a fine dust. All this would happen in essentially freefall time. Come on, read your NIST.
I think it depends on whether or not a cave in Afghanistan harbors an Arab terrorist who hates our freedom. You have to understand that there's a before 9/11 and an after 9/11 and after 9/11 everything's different.
You don't need logic, math, or physics when you're being attacked by Evil Terrorists, Spooked. You should know that by now.
Fred
I think it depends on whether or not a cave in Afghanistan harbors an Arab terrorist who hates our freedom. You have to understand that there's a before 9/11 and an after 9/11 and after 9/11 everything's different.
You don't need logic, math, or physics when you're being attacked by Evil Terrorists, Spooked. You should know that by now.
Fred
Ah, right!
Thanks, Fred, for the reminder!
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