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Height of Building/ Time Period/Battle over a Theorem

 
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sikandarsiddiqi
...
...


Joined: 26 Jan 2003
Posts: 294

PostPosted: Sat Sep 18, 2004 5:05 pm    Post subject: Height of Building/ Time Period/Battle over a Theorem Reply with quote

Radio Link International E-mail

Dateline

Dhaka- Bangladesh/Asia

CLASSIFIED & IMPORTANT

"Speak out on an issue you feel strongly about, be it technical, ethical or professional. Raise issues that you believe need to be discussed" - SEFI Guide Line



Dear Engr.Aswin, > Los Angeles, California,USA

Thank you for your e-mail,from halfway around the world, which is quite interesting as it has opened a battle over a time tested theorem.

I find you have somehow misinterpreted my transmission ; meanwhile it will be best for Engr.Mukesh Upadhyay to wait as my SPECIFIC  REPLY will be flashed within a couple of days.A slopped roof is only valid in seismic architecture when it will comply with terms & conditions as outlined in the theorem otherwise it will be incorrect architecture which may lead to a catastrophic failure.

Think of  ' Titanic ' disaster ,' Columbia' space shuttle disaster operated by NASA, failure of robotic 'Beagle' mission to the planet Mars operated by the European Space Agency - all failed because of design & technical mismanagement and under estimate as per enquiry commission report.Another recent example is' WTC - Twin Tower' which was neither heat resistant nor impact proof - fault of structural design management engineer and appropriate administrative command,failure of imagination,failure of policy,failure of capability,failure of safety system approach & connectivity etc. ( Watch 'SHOCKING' on AXN TV Channel for back up safety measures ).Please note that all the above projects were designed by highly trained engineers and related technical persons but what caused each to fail under specific condition/s; something is wrong somewhere along the axis of judgement - this is a question indeed now being asked by every one irrespective of race, culture and nation world wide.

With best wishes from far away Dhaka,Bangladesh.
Engr.Sikandar Hayat Siddiqi
Project & Seismic Design Management Engineer
&
Builder/Developer Selection Consultant
&
Co-ordinator,Earthquake Anti-disaster Defence Management System Initiative
&
Director,Special Monitoring System



Original Message
To:sikandarsiddiqi@yahoo.comSubject: Re: Height of Building/ Time PeriodFrom:aswinpe@hotmail.com Date:Fri Sep 17   03:26:08   2004



Copy to :

Engr.Himali V Bhatt,India (himali.joshi@babtieindia.com) Engr.Alpa Sheth,India, ( alpa_sheth@vakilmehtasheth.com )

Engr.Mukesh Upadhyay,India ( mc.upadhyay@jil.co. )


Engr.Abhyankar Vivek,India ( ABHYANKAR@hccindia.co.in)

Engr.Hardik Choksi,India (talk2hard@hotmail.com)

Engr.Rudra Nevatia,India (rudra_nevatia@yahoo.com)

Engr.Sangeeta,India (sdec@bol.net.in)

Prof.Dr.Engr.Sudhir K Jain, IITK, India (skjain@iitk.ac.in)

Engr.Pankaj Gupta, SEFI, India (admin@sefindia.org)

Engr.Sanjayjha,GovernmentofDelhi (hqadm@hub.nic.in)

Mr.Stacey Martin, Director, ASC (martin@asc-india.org)

Engr.Anup Karanth (anup.karanth@undp.org)






aswinpe@hotmail.com wrote: Hello:

It is extremely incorrect to state that "In seismic design a slopped roof
is incorrect architecture.." I am an engineer in California which has been
rocked by several earthquakes. The roof of almost every residential
structure is sloped. According to your theory all these structures should
have failed?

The problem in roof during a seismic event arises when there is two or more
horizontal diaphragm levels (roof) which are not tied together properly to
transfer the shear forces to the vertical resisting system (walls/frames).
For example if there is a mechanical well in the middle of the roof and the
roof diaphragms are not tied together then the load path is affected. So a
sloped roof is perfectly acceptable and has performed very well if the load
path has been properly detailed to carry the forces to the walls and then to
the foundation.

Now to answer Mr. Mukesh Upadhyay's question of the height. The formula for
the period of a structure is an approximate method and in a sloped structure
it might be conservative to take the maximum height

Hope it helps.

- Aswin
_____________________________
Aswin Rangaswamy, P.E.
Los Angeles, California

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aswinpe
SEFI Regulars
SEFI Regulars


Joined: 26 Jan 2003
Posts: 28

PostPosted: Tue Sep 21, 2004 12:30 am    Post subject: Height of Building/ Time Period/Battle over a Theorem Reply with quote

Dear Engr.Sikandar Hayat Siddiqi:

It is very interesting to read your response to my mail but the examples you
have given seem to be out of the subject being discussed here "Sloping roofs
in seismic areas".

I find it quite surprising and offending to note that you have classified
WTC as a structural engineering failure due to the "structural design
management engineer and appropriate administrative command,failure of
imagination,failure of policy,failure of capability,failure of safety system
approach & connectivity etc.".  If I may, I would like to educate you on
this mistaken concept.

There were an estimated 58,000 people in the twin towers when the building
came under attack.  The fire ignited by the jet fuel burned the contents of
the building.  Out of this 2830 people died including 403 emergency
responders (fire, police etc).  The majority of the people killed were in
the floor that was hit or above (only about 4 people got down from the floor
above, they could not get down since the stairs in the middle were damaged.
There is no way a building can be built within reasonable cost to sustain
such an attack - this is comparable to a missile strike.

The building was able to stand up for over an hour so that more than 95% of
the occupants were able to get out safetly.  This is because of the
excellent structural design and construction.  These words are actually from
one of the reports released from the WTC study.

So please do not spread this word around and put the structural engineers in
an ackward position in front of the ingnorant public.

In a seismic design, the only thing that prevails is "a complete load path
capable of transferring all loads and forces from their point of origin to
the load-resistig elements".  So somehow, i still dont see your point of
view on sloping roofs.  Are there not any dome roofs which slope and they
have also stood the test of several earthquakes.

I also feel that the theorem that you have stated makes the work of
structural engineers obselete since if everything is on the same plane there
is not need for engineers to design anything Smile.  In my experience,
structural engineers make the dream of architects a reality.  The enclosed
link is from the Disney Concert hall in Los angeles -
http://wdch.laphil.com/wdch/  Looks at the slopes and curves of this
building.  This has not been through a seismic event yet Sad.

I dont look at this as a "Battle" like you have suggested.  I have provided
example of sloping structures which have withstood several earthquakes and
talking about a practical solution and not a theorem discussed in a book.
Probably we both are talking about different thiings.  I have included a
sketch of a simple two level building with sloping roof.


*               Top of Sloping Roof
*    *
*          *
*                *
*                     *
************    Ceiling of 1st Floor
*                     *
*                     *
*                     *
*                     *
* ***********   1st Floor
*                     *
*                     *
*                     *
*                     *
* ***********   Ground Floor

Hope this clears up any confusion.

Regards,

- Aswin
_____________________________
Aswin Rangaswamy, P.E.
Los Angeles, California

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James_Cohen
SEFI Regulars
SEFI Regulars


Joined: 26 Jan 2003
Posts: 31

PostPosted: Wed Sep 22, 2004 1:52 pm    Post subject: Height of Building/ Time Period/Battle over a Theorem Reply with quote

To those who replied to Engr. Siddiqi:

I would like to add a short response as one of the first responders to the
9/11 tragedy, in the role of Structures Specialist to the New Jersey Urban
Search and Rescue Team. One aspect of the collapse which is often missed was
the integrity of the entire complex. The twin towers were not stand alone
structures. They were tied in to the multi-level underground complex which
included shopping areas, parking, subway stations, surrounding buildings,
etc. During the searches we made for survivors/victims within the lower
levels, we also made inspections of the surrounding retaining slurry walls
had an additional function to retain the Hudson River as there were worries
that these might fail with resulting flooding in the WTC complex and NYC
subway system. Despite the collapses of the twin towers, the underground
complex remained largely intact, as did the slurry wall system.

James Cohen, PE
James Cohen Consulting, PC
http://expertpages.com/jccpc

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sikandarsiddiqi
...
...


Joined: 26 Jan 2003
Posts: 294

PostPosted: Fri Sep 24, 2004 4:21 pm    Post subject: Height of Building/ Time Period/Battle over a Theorem Reply with quote

Radio Link International E-mail

Dateline

Dhaka- Bangladesh/Asia

CLASSIFIED & IMPORTANT

"Speak out on an issue you feel strongly about, be it technical, ethical or professional. Raise issues that you believe need to be discussed" - SEFI Guide Line

SEFI offers you a whole new dimension for approaching issues of concern. Whenever you need quality inputs, the combined resource of SEFI members would be a useful sounding board - SEFI

Call for volunteers : Members who are interested in volunteering 5 to 10 hours a week for the website development work for SEFI, please email to admin@sefindia.org

Call for Articles : Members who may be interested in contributing Articles to SEFI website, may email the Articles to admin@sefindia.org

Prof.Dr.Jain writes " Therefore, I reiterate my earlier appeal of  February and request all members to consider contributing a sum ranging from Rs 200/- to Rs 2,000/- to SEFI."" The amount may please be sent by a cheque or draft in favour of
Structural Engineers Forum of India" payable at Bombay.
The drafts/cheques should be sent
to
Ms. Alpa Sheth
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Mumbai 400 023

Prof.Dr.Jain writes " However, to save efforts, we will also accept outstation cheques."




Dear Engr.Aswin, > Los Angeles, California,USA

Thank you for your e-mail from far away US city Los Angeles along coast line of the Pacific.

I find you have converged on the theorem; this is the conclusion being drawn from the sketch you have provided in your e-mail text.This will be more clear to you once you receive 'SPECIFIC REPLY' in response to your earlier one as I mentioned in my previous e-mail which will be transmitted shortly in due course.

On the other hand I find this e-mail of yours very interesting for which an 'ANALYTICAL REPLY' reply will be radioed very soon.



With regards and best wishes.


Engr.Sikandar Hayat Siddiqi
Project & Seismic Design Management Engineer
&
Builder/Developer Selection Consultant
&
Co-ordinator,Earthquake Anti-disaster Defence Management System Initiative
&
Director,Special Monitoring System



Copy to :

Engr.Himali V Bhatt,India (himali.joshi@babtieindia.com) Engr.Alpa Sheth,India, ( alpa_sheth@vakilmehtasheth.com )

Engr.Mukesh Upadhyay,India ( mc.upadhyay@jil.co.in )


Engr.Abhyankar Vivek,India ( ABHYANKAR@hccindia.co.in)

Engr.Hardik Choksi,India (talk2hard@hotmail.com)

Engr.Rudra Nevatia,India (rudra_nevatia@yahoo.com)

Engr.Sangeeta,India (sdec@bol.net.in)

Prof.Dr.Engr.Sudhir K Jain, IITK, India (skjain@iitk.ac.in)

Engr.Pankaj Gupta, SEFI, India (admin@sefindia.org)

Engr.Sanjayjha,GovernmentofDelhi,India (hqadm@hub.nic.in)

Mr.Stacey Martin, Director, ASC,India (martin@asc-india.org)

Engr.Anup Karanth,India (anup.karanth@undp.org)

Engr.James Cohen, PE,USA (jccpc@msn.com)

Engr.Aswin Rangaswamy,PE,USA (aswinpe@hotmail.com)  






*Original Message*

From:"Aswin Rangaswamy" <aswinpe@hotmail.com> To:general@sefindia.orgCC:sikandarsiddiqi@yahoo.comSubject:Re: Height of Building/ Time Period/Battle over a TheoremDate:Mon, 20 Sep 2004  17:07:37 -0700



aswinpe@hotmail.com wrote:

Dear Engr.Sikandar Hayat Siddiqi:

It is very interesting to read your response to my mail but the examples you
have given seem to be out of the subject being discussed here "Sloping roofs
in seismic areas".

I find it quite surprising and offending to note that you have classified
WTC as a structural engineering failure due to the "structural design
management engineer and appropriate administrative command,failure of
imagination,failure of policy,failure of capability,failure of safety system
approach & connectivity etc.". If I may, I would like to educate you on
this mistaken concept.

There were an estimated 58,000 people in the twin towers when the building
came under attack. The fire ignited by the jet fuel burned the contents of
the building. Out of this 2830 people died including 403 emergency
responders (fire, police etc). The majority of the people killed were in
the floor that was hit or above (only about 4 people got down from the floor
above, they could not get down since the stairs in the middle were damaged.
There is no way a building can be built within reasonable cost to sustain
such an attack - this is comparable to a missile strike.

The building was able to stand up for over an hour so that more than 95% of
the occupants were able to get out safetly. This is because of the
excellent structural design and construction. These words are actually from
one of the reports released from the WTC study.

So please do not spread this word around and put the structural engineers in
an ackward position in front of the ingnorant public.

In a seismic design, the only thing that prevails is "a complete load path
capable of transferring all loads and forces from their point of origin to
the load-resistig elements". So somehow, i still dont see your point of
view on sloping roofs. Are there not any dome roofs which slope and they
have also stood the test of several earthquakes.

I also feel that the theorem that you have stated makes the work of
structural engineers obselete since if everything is on the same plane there
is not need for engineers to design anything Smile. In my experience,
structural engineers make the dream of architects a reality. The enclosed
link is from the Disney Concert hall in Los angeles -
http://wdch.laphil.com/wdch/ Looks at the slopes and curves of this
building. This has not been through a seismic event yet Sad.

I dont look at this as a "Battle" like you have suggested. I have provided
example of sloping structures which have withstood several earthquakes and
talking about a practical solution and not a theorem discussed in a book.
Probably we both are talking about different thiings. I have included a
sketch of a simple two level building with sloping roof.


* Top of Sloping Roof
* *
* *
* *
* *
************ Ceiling of 1st Floor
* *
* *
* *
* *
* *********** 1st Floor
* *
* *
* *
* *
* *********** Ground Floor

Hope this clears up any confusion.

Regards,

- Aswin
_____________________________
Aswin Rangaswamy, P.E.
Los Angeles, California

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sefi_admin
Site Admin
Site Admin


Joined: 23 Apr 2008
Posts: 70

PostPosted: Fri Sep 24, 2004 5:56 pm    Post subject: Height of Building/ Time Period/Battle over a Theorem Reply with quote

Dear Mr. Siddiqi,

I have 2 requests to make to you:

1) For any email that you post on the forum, there is actually no point in
sending copies of the same, directly to members of the forum, as whatever is
posted to the forum is anyway received by them through the forum. So it
creates unnecessary duplicacy.

2) SEFI is a voluntary organization (& quite informal too), and runs on very
meager resources in terms of both funds & manpower. The web expenses for the
website & all the emailing is directly proportional to the amount of data
transferred thru the website. So it would be helpful, if the members say
to-the-point things & not post unnecessarily long & official style emails.
Thats why we also request to delete the whole thread of the topic (except
the one to which they reply, to keep things in context) from their emails.
If you notice the general size of the emails posted in the forum are within
2-3KB range. An increase of say just 10 KB for a single post translates to
9.25 MB of traffic, as each email is transmitted to 925 members.

I hope you & other members will appreciate the situation & cooperate
accordingly.

Regards

Pankaj Gupta
admin@sefindia.org

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