Design parameters of the twin towers. Other than the fema reports,
that contributed to the collapse of the World Trade Centre.There is
much material on this subject but i require something original, that
appears to have good engineering reasoning and is not so easy to find

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Request for Question Clarification by aceresearcher-ga on 16 Apr 2003 13:59 PDT

Greetings, johanna1!

Most such engineering reports are original works, written by the
authors named on their cover or first page. Can you give us a better
idea of what characteristics would qualify a report as "original"?

Thanks,

aceresearcher

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Request for Question Clarification by knowledge_seeker-ga on 16 Apr 2003 16:27 PDT

HI johanna1-ga,

I'm a bit confused by your phrase, "not so easy to find." 

To whom? 

Many of the things that we researchers consider "easy to find"
obviously are not easy to most of the customers who come here.
Otherwise they wouldn't be asking.

And a report in an Engineering Journal may be hard for me to find, not
having access to one, but would be easy for say a Professor of
Engineering or the owner of an Engineering firm.

Maybe you could be a bit clearer on that point?

Thanks -K~

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Clarification of Question by johanna1-ga on 17 Apr 2003 03:19 PDT

Hello aceresearcher,
"original" may not be the exact word, but i am looking for something
with a different but feasable slant on the collapse of the towers.
Such as fire,construction of buildings,wether the "core" construction
is still deemed to be viable. Really a sound engineers report in
layman's terms as opposed to the mind boggling jargon within the fema
reports.
Regards johanna1

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Clarification of Question by johanna1-ga on 17 Apr 2003 03:41 PDT

Hello Knowledge seeker,
By " not easy to find". I mean that there is a wealth of information
on this subject such as fema reports, but a sound engineering report
in layman's terms. That i would envisage would be well within your
skills, but may lie outside of mine to find. By this i mean something
that would not immediately present itself. I realise this is why
people use google answers.However i feel the need to emphasise this
point as there is such a wealth of info. on the internet.
Regards johanna1

johanna
  
            I will take a chance on your intuitive question.
  
A description of the structure and the collapse by a professor
of CE at the University of Sydney provides a good technical
 yet readable summary:
    World Trade Center - Some Engineering Aspects 
http://www.civil.usyd.edu.au/latest/wtc.php

References, links at the bottom, lead to the engineering analysis
which may be at variance with the official analysis. Example of
that is hypothesis that thermal insulation was insufficient:
   "..If confirmed, it could also lead to changes in building codes.
NIST is responsible for drawing up the final report on the towers'
collapses and recommending if any changes are needed..."
http://www.newscientist.com/news/news.jsp?id=ns99993354

Need for building code changes and high rise safety will be discussed
for a long time, but one piece of the 'conventional wisdom' namely:

 'Elevators are recalled to the lobby .. when the fire alarm is
activated ..'
www.cityofseattle.net/fire/pubEd/brochures/ high%20rise%20tenants.pdf

or

 ... Walk down to lobby level, NEVER use the elevator  
www.cityofreno.com/pub_safety/fire/ risk_reduc/home/high_rise/

 was shown  not applicable to very high buildings. An evacuation
system is
 needed which is faster then stairways and which functions on
emergency
 power or gravity power when normal power supply is cut. Such system
may
 require sophisticated smoke sensors and fire-proof elevator lobbies
as
 well as technical means preventing smoke and fire from spreading
through
 the shafts. Such Egress Systems were proposed even before 9/11:

 Levin, Bernard M. & Groner, Norman E., September, 1997
 SOME CONTROL AND COMMUNICATION CONSIDERATIONS IN
DESIGNING AN ELEVATOR EVACUATION SYSTEM, Elevator World pp110

or

 Proulx, G.
 EVACUATION TIME AND MOVEMENT IN APARTMENT BUILDINGS, Fire
Safety Journal, Vol. 24, 1995, pp. 229 - 246

 After the WTC tragedy the need for change is clear:  

"  GET THE PEOPLE OUT BEFORE THE FLOORS COLLAPSE

 City Council of New York City should hold hearings and propose
legislation requiring the evacuation of all occupants from a high rise
office building to be accomplished within the maximum time a floor in
the building can resist fire..."
http://vincentdunn.com/dunn/life_safety1_of_2002.htm

It seems that changes so far adopted did not embraced this
recommendation:
"... point 8: The building code should require high-rise buildings to
have a so-called phase III elevator. This phase III elevator is an
elevator that could be used by firefighters for access to upper
floors, and most importantly used by disabled persons for evacuation
during fires and terrorist incidents. A phase III elevator is one
enclosed by walls that protected it from toxic fumes, smoke, fire and
water..."
 http://www.nyc.gov/html/dob/html/dunn.html

In concusion

 Original and inovative engineering studies, proposals and designs are
 needed, which can evacuate people from large and tall buildings and
areas
 in time shorter then the 'time to collapse' in case of the
uncontrolable
fire. In cases such as new WTC, interconnection of such 'egress
systems' to
the horizontal transport, such as metro, should be able to move large
number of people away from the danger area in the shortest possible
time.

Thank you for a thought provoking question.

Search Terms
Fire safety, elevators, high rise
engineering analysis, building collapse

hedgie

A number of technical engineering studies have been conducted into the
reasons for the collapses of the WTC towers 1, 2 and 7. Two were
performed by litigants over the insurance claims, the primary
leaseholder Silverstein Properties and the Swiss insurer. The
Silverstein study contradicts the FEMA study. Neither of the two
studies appears to be available to the public, however. The
conclusions are public, howvever.


Basic Design

structurae:One World Trade Center (English Version)
http://www.structurae.de/en/structures/data/str00088.php
Design features and an extensive set of links to articles about the
collapses.


LERA-ASCE
The Collapse of the World Trade Center Towers
Frequently Asked Questions 
http://www.lera.com/asce.html

Collapse of the World Trade Center
http://www.civil.usyd.edu.au/latest/wtc.php

NIST and the World Trade Center - revised 2/25/2003
http://wtc.nist.gov

NOVA Online|Why the Towers Fell|Resources|PBS
http://www.pbs.org/wgbh/nova/wtc/resources.html

American Society of Civil Engineers
http://www.asce.org/responds

House Committee on Science
http://www.house.gov/science/hot/wtc/

McGraw-Hill Construction|ENR
Report Ties Trade Center Collapses to Column Failures(10/25/2002)
http://www.enr.com/news/buildings/archives/021025.asp

"The collapses of the 110-story twin towers of the World Trade Center
after terrorists slammed hijacked planes into them were separately
initiated in the impact zone of each tower due to failure of the
columns, says a recent engineering report, not the floor trusses."
[...]
"The team determined that the initial hits destroyed 33 of 59
perimeter columns in the north face of One WTC and 29 of 59 perimeter
columns in the south face of Two WTC. Computer analysis showed that
the impact of the planes also destroyed or disabled some 20 of 47
columns in the center of the core of One WTC and some five of 47
columns in the southeast corner of the core of Two WTC. The crashes
stripped fireproofing from columns in the path of       debris created
by the planes penetrating the buildings, it continues."
[...]
"The engineering team is comprised of: Weidlinger Associates Inc., led
by Matthys Levy and Najib Abboud; LZA Technology/Thornton-Tomasetti
Group, led by Daniel Cuoco and Gary Panariello; ARUPFire, led by
Richard Custer; Hughes Associates Inc., led by Craig Beyler;
SafirRosetti, led by Howard Safir; Hillman Environmental Group, led by
Christopher Hillmann and John B. Glass Jr.; RWDI, led by Peter Irwin;
Dr. W. Gene Corley, who led the ASCE-FEMA study; Professor Sean
Ahearn; and Z-Axis Corp., led by Gary Freed and Alan Treibitz."


Weidlinger Associates, Inc.
http://www.wai.com

The Civil Engineering Portal - News - WTC
http://www.icivilengineer.com/News/WTC/structure.php

New Scientist
Twin tower collapse theory challenged
http://www.newscientist.com/news/news.jsp?id=ns99993354

"No one doubts that the planes killed many people on impact and
started the fires that led to the buildings' collapse, says Quintiere.
But if both towers had had insulation over 50 millimetres thick, he
says, they might not have collapsed at all. His analysis calls into
question the safety of other buildings constructed to the same
standards as the twin towers. However, the Port Authority of New York,
the owner of the twin towers, rejects his theory.

Quintiere, whose previous work includes investigating the 1993 fire at
the Branch Davidian compound in Waco, Texas, was struck by a statement
in last year's preliminary report of the Federal Emergency Management
Agency (FEMA). It noted that there was a discrepancy in the thickness
of the fireproofing in the towers. On the floors of the south tower
where the plane hit it was just 19 millimetres thick, half that on the
floors struck in the north tower."
[...]
"The results, presented in June 2002 at a meeting in New York
organised by NIST, have now been published in Fire Safety Journal (vol
37, p 707). The team calculated that the south and north towers would
collapse after 75 and 115 minutes respectively. In fact, they fell
after 56 and 103 minutes. "It's the only calculation I've seen that
has any correlation with events," Quintiere says."

Forums and Webcast

Forum on the Technical Implications of the World Trade Center
Collapses
http://www.civil.columbia.edu/wtcforum/

Les Robertson Speaks at the National Council of Structural Engineers
Association Conference.  A student’s perspective.
http://www.engr.psu.edu/ae/WTC/LERPresentation.htm

hlabadie-ga