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Sikkim Earthquake Sept 18 2011
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francis chacko
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PostPosted: Mon Sep 19, 2011 3:58 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

 A VERY GOOD IDEA.IN FACT AS MUCH DETAILS AS POSSIBLE INCLUDING PHOTOGRAPHS SHOULD BE COLLECTED. ENGINEERS NEAR BY LOCATIONS SHOULD TAKE INTEREST AND LET US BE KNOWN.

AS PROF. ARC INFORMED THE CAUSE FOR FAILURE OF MOBILE NET WORK MAY BE DUE TO THE COLLAPSE OF MOBILE TOWERS.

 I AM AFRAID THAT THERE ARE MANY MOBILE TOWERS IN THE COUNTRY ERECTED ON THE EXISTING BUILDINGS WITH OUT HAVING PROPER STRUCTURAL ANALYSIS.

K C FRANCIS



On Sun, Sep 18, 2011 at 9:58 PM, alpa_sheth <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote:
           Dear All 

You must have by now heard of the 6.8 Magnitude earthquake with epicentre in Sikkim 68 km NW of Gangtok.
We pray and  hope that there is min damage and loss of lives. We request all SEFI members in Northeast, W Bengal, North India to share their experiences of the earthquake- both personal as well as observations of any damage etc. 
We hope in this way SEFI can become a repository of personal earthquake experiences of structural engineers. We will create a special page for this after collating all information.


Thanks much in advance,
best regards and keep safe. 


Alpa Sheth, 
on behalf of SEFI Admin. 
     



     



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rni
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PostPosted: Mon Sep 19, 2011 5:43 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

Request to those in charge of Strong Motion instruments in NE. Please post
the records publicly with details.

Thanks

RN Iyengar

[quote]Dear All 

You must have by now heard of the 6.8 Magnitude earthquake with epicentre
in Sikkim 68 km NW of Gangtok.
We pray and  hope that there is min damage and loss of lives. We request
all SEFI members in Northeast, W Bengal, North India to share their
experiences of the earthquake- both personal as well as observations of
any damage etc. 
We hope in this way SEFI can become a repository of personal earthquake
experiences of structural engineers. We will create a special page for
this after collating all information.


Thanks much in advance,
best regards and keep safe. 


Alpa Sheth, 
on behalf of SEFI Admin. 

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bipinsh
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PostPosted: Mon Sep 19, 2011 6:06 am    Post subject: Reply with quote

Dear sefians,

Uptill now there has been 3 casulties in kathmandu. 3 people buried under the collapsed British embassy wall and 2 more died in sunsari.(south east part in Nepal).
We at Kathmandu felt moderate shaking nearly for a minute. eventhough the shaking was not intense the duration was considerable one. there are reports of cracks in older masonry houses and also collapse of older building including the collapse of British embassy wall causing 3 deaths.

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Regards

Bipin
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atul_123
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PostPosted: Mon Sep 19, 2011 6:16 am    Post subject: Reply with quote

video

ndtv news

http://www.ndtv.com/video/player/news/how-india-experienced-the-sikkim-earthquake/211196

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vikram.jeet
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PostPosted: Mon Sep 19, 2011 6:48 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

Our sympathies with those affected by this Nature's devastation
as result of EQ event which is still un-predictable by any means
in this modern world of advancement and research. Scientists/
seismologists are still in dark about WHEN, WHERE, HOW much

As per personal view as a layman on seismology:
EQ is result of underground disturbance of plates .Probably if one plate
adjust wrt to other one , the EQ just pass off .Recently some feeble
intensity (4.2 on scale) struck Delhi/ NCR few days back with epicenter
at Sonipat and duration of 3-4 seconds The wave just passed off like
a thud and it was felt by even those ,fast asleep
But if one plate adjust wrt to other one and other one also adjust in response,
there is wave propagation , the EQ becomes devastating if duration
becomes more. Bhuj devastating EQ of 2003 was long duration
EQ motion

Though Gangtok is placed on Zone IV of EQ Map , buildings are not built  
as per norms and problem is further worsened by appendages like mobile
towers ,chimneys on roof tops as discussed by respected Prof ARC sir
in his posting.

Rains hamper the rescue operations as per reports.


vikramjeet




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partha
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PostPosted: Mon Sep 19, 2011 8:00 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

Yesterday there were three major Earthquakes (with Magnitude 4.5 or greater) in quick successions, accompanied by some weaker aftershocks.  

<![if !supportLists]>- <![endif]>First one had magnitude 6.9, Originated at 27.723°N, 88.064°E (19.7 km depth) which is 572 km away from Kolkata. Time at Epicentre: 06:25:48 PM
<![if !supportLists]>- <![endif]>Second one had magnitude 4.8, Originated at 27.446°N, 88.391°E (20 km depth) which is 541 km away from Kolkata. Time at Epicentre: 06:41:57 PM
<![if !supportLists]>- <![endif]>Third one had magnitude 4.6, Originated at 27.377°N, 88.266°E (20.1 km depth) which is 533 km away from Kolkata. Time at Epicentre: 07:24:18 PM

For the first one, with highest Magnitude USGS immediately released pager with ORANGE Alert for Nepal, Sikkim and North Bengal. In terms of Structural Damage, major Towns which have light impact (BLUE Alert) are Kathmundu, Thimpu, Patna, Bhalgalpur and Muzaffarpur. There was no RED ALERT. Refer to the attached PDF for further details.  

Though the shaking is felt in Kolkata, apparently there is no threat even for vulnerable structures (like masonary buildings, huts or temporary structure).  

Partha


From: rni [mailto:forum@sefindia.org]
Sent: 19 September 2011 11:29
To: general@sefindia.org
Subject: [SEFI] Re: Sikkim Earthquake Sept 18 2001


Request to those in charge of Strong Motion instruments in NE. Please post
the records publicly with details.

Thanks

RN Iyengar

Quote:
Dear All

You must have by now heard of the 6.8 Magnitude earthquake with epicentre
in Sikkim 68 km NW of Gangtok.
We pray and hope that there is min damage and loss of lives. We request
all SEFI members in Northeast, W Bengal, North India to share their
experiences of the earthquake- both personal as well as observations of
any damage etc.
We hope in this way SEFI can become a repository of personal earthquake
experiences of structural engineers. We will create a special page for
this after collating all information.


Thanks much in advance,
best regards and keep safe.


Alpa Sheth,
on behalf of SEFI Admin.  







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SATISH MADHAVRAO KULKARNI
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PostPosted: Mon Sep 19, 2011 3:06 pm    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

Dear All SEFIans,
It is seen that in the event of disaster due to earthquake communication systems used to damage severely.
There is a long and long record of communication loss and hindrances in getting the correct data of severity of the situation.
HAM Radio is really a proved and reliable solution   to meet the emergency solution for telecommunication. Government organisations,
NGOs should come forward and promote the use of HAM Radio. I am providing herewith the contact details of 
National Institute of Amateur Radio.
Shri S. Suri , S. Yamini and others are ready to extend cooperation to promote this essential venture.


National Institute of Amateur Radio 
Raj Bhavan Road, Somajiguda 
Hyderabad 500082, INDIA 

Telefax: 91-40-2331 0287  Tel: 91-40-65167388
E mail: niarindia@hotmail.com (niarindia@hotmail.com), vu2nro@gmail.com (vu2nro@gmail.com
Web site: www.niar.org 
Club station: VU2NRO 14160 kHz, 144.720 MHz. Echolink: Node 133507
 


On Mon, Sep 19, 2011 at 1:49 PM, vikram.jeet <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote:
           Our sympathies with those affected by this Nature's devastation
as result of EQ event which is still un-predictable by any means
in this modern world of advancement and research. Scientists/
seismologists are still in dark about WHEN, WHERE, HOW much

As per personal view as a layman on seismology:
EQ is result of underground disturbance of plates .Probably if one plate
adjust wrt to other one , the EQ just pass off .Recently some feeble
intensity (4.2 on scale) struck Delhi/ NCR few days back with epicenter
at Sonipat and duration of 3-4 seconds The wave just passed off like
a thud and it was felt by even those ,fast asleep
But if one plate adjust wrt to other one and other one also adjust in response,
there is wave propagation , the EQ becomes devastating if duration
becomes more. Bhuj devastating EQ of 2003 was long duration
EQ motion

Though Gangtok is placed on Zone IV of EQ Map , buildings are not built
as per norms and problem is further worsened by appendages like mobile
towers ,chimneys on roof tops as discussed by respected Prof ARC sir
in his posting.

Rains hamper the rescue operations as per reports.


vikramjeet




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Dr. N. Subramanian
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PostPosted: Mon Sep 19, 2011 3:26 pm    Post subject: Re: Sikkim Earthquake Sept 18 2001 Reply with quote

Hi All,

A man shows cracks in the wall of his house in Siliguri. Photo: PTI
[Quake toll climbs to 71, rescue work hampered by landslides Sikkim alone accounted for 39 deaths; six deaths in West Bengal and seven each in Bihar, Nepal and Tibet, were reported; over a hundred people have been injured]

I also express my sympathies to all those who are affected in someway or other by the earthquake in Sikkim.

The failures of Mobile Communication towers  located on Roof tops of existing buildings as pointed out by Prof. ARC has to be considered seriously as communication during such events is more important. Perhaps BIS should issue a standard for such Appendages.

IS Code for communication towers is also lacking- I have seen a draft more than 20-25 years ago but it is yet to be finalized!

Best wishes
Subramanian

prof.arc wrote:
1. We express our sympathies with all those who are affected in someway or other - loss of life/injuries/loss of property

2. Theoretically the event is no surprise - since the first version of IS:1893, the region is identified as in the severest seismic zone.
3. This is definitely not the maximum potential event for that region - could be called as an event that would occur during the life time of structure
4. From an engineering point of view, this event could be known for changes that must come for APPENDAGES - Towers for Mobile Communications  located on Roof of existing Structures. [the Bhuj event, brought our attention to STILT Buildings


COMMUNICATION TOWERS LOCATED AS APPENDAGES
The first reports on TV indicated wide spread disruption of mobile communications due probably to failure of Towers.
The operators found it cheaper - no need to acquire land and the owners were happy to get easy funds and we see that most such towers are located on top of existing buildings [which buildings were not originally designed to support such appendages]


(A) The failure in this Sikkim event could be due of failure of structure or the towers causing failure to the structure
This could be found out by field survey - behaviour of nearly identical structures - some not having the tower appendage
[We have a most notable experience - among the various monoliths of non-overflow sections of Koyna Dam, only M-17 which had a tall observation tower as an appendage suffered damage]  
(B) I presume that the design of such appendage on the strength of the structure must be cursory -
I wish and strongly urge an immediate research program by IIT-Guwahati on proper modelling of Towers on the roof of different type of buildings
that exist in Brahmaputra Plains of Guwahati and the hills of Shillong
The adhoc and arbitrary clauses of IS:1893 for Appendages are not valid


(C) The authorities should insist on free standing Mobile Communication Towers for important locations of administration.

Mobile communication is not a luxury - it is used by Aam Admi


On a lighter note, BSNL should be happy that their land lines mostly functioned


ARC


On Sun, Sep 18, 2011 at 9:58 PM, alpa_sheth <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote:
            Dear All

You must have by now heard of the 6.8 Magnitude earthquake with epicentre in Sikkim 68 km NW of Gangtok.
We pray and  hope that there is min damage and loss of lives. We request all SEFI members in Northeast, W Bengal, North India to share their experiences of the earthquake- both personal as well as observations of any damage etc.
We hope in this way SEFI can become a repository of personal earthquake experiences of structural engineers. We will create a special page for this after collating all information.


Thanks much in advance,
best regards and keep safe.




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PostPosted: Tue Sep 20, 2011 12:44 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

1. I am aware that the attention of all in administration MUST be on relief and they are not expected to do post-mortem regarding why failures have taken place even in so called engineered structures.

2. One thing that could be predicted - failures would be confined only to so called engineered structures wherein techniques that are mainly suitable in plains has been transplanted to hilly terrain.
3. In my long experience of field survey between late fifties starting with Badgam earthquake and late nineties, [even later confirmed by reports - NICEE report of earthquake of POK Kashmir], the older type of construction of religious places - temples/pagodas/mosques have least or no damage.
It is because they followed construction practices handed over to them from times immemorial - mainly braced wooden construction.
4. I am VERY STRONGLY in favour of braced wooden construction only for Aam Janata. The material is locally available - instead of exporting it to plains for profit, it must be given at subsided rates to locals.
5. Bulk of suburban buildings in severe seismic regions in USA / Japan are of wooden construction only.
6. I sincerely hope that the Govt and Academic/Research teams would highlight those structures which WITHSTOOD the event rather on parroting on failed constructions. One can almost predict all such failures of modern construction without a visit to the site.
We learn much more from structural behaviour of systems that had minimum damage.
7. Human beings are eternally optimistic - they would find a way to recover from this tragedy and rebuild. LET THEM REBUILD WISELY.


ARC 

On Sun, Sep 18, 2011 at 9:58 PM, alpa_sheth <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote:
           Dear All 

You must have by now heard of the 6.8 Magnitude earthquake with epicentre in Sikkim 68 km NW of Gangtok.
We pray and  hope that there is min damage and loss of lives. We request all SEFI members in Northeast, W Bengal, North India to share their experiences of the earthquake- both personal as well as observations of any damage etc. 
We hope in this way SEFI can become a repository of personal earthquake experiences of structural engineers. We will create a special page for this after collating all information.


Thanks much in advance,
 best regards and keep safe.

 Alpa Sheth, 



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sikandarsiddiqi
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PostPosted: Tue Sep 20, 2011 3:33 am    Post subject: Sikkim Earthquake Sept 18 2001 Reply with quote

IN GOD WE TRUST,
PARDON,PROTECT & HELP US LORD,
GOD, GIVE US THE WISDOM TO UNDERSTAND YOUR WAY OF CREATION WHICH
WE CALL SCIENCE,
LETS PRAY FOR ALL THOSE WHO ARE SICK FOR EARLY RECOVERY & IN DISTRESS.
HELP SOME ONE IN POVERTY LEVEL
.

Dear Engr.Francis Chacko and Prof ARC > India

My attention has been drawn to this special mail.

Same thing happened in Dhaka too immediately after the earthquake at least for three hours.Upon investigation,I found it was due to over load upon the network as so many users were criss-crossing over phone to contact their relatives,friend and othersthe result was self automated electronic jamming.

Off course,some network connection in some areas may fail due to damage or structural failure of the tower/s.

Lot of thanks to you and Prof Arc for this strategic technical information.


With this much regards & best wishes.



God Bless us all.
Engr.Sikandar Hayat SiddiqiChief Seismic Technical Co-ordinator, Earthquake & Tsunami Safety Management Initiative (ETASMI)/ Chief Technical Co-ordinator, ETASMI Data Center /Chief Executive, ETASMI Information Service /Project & Seismic Design Management Engineer / Earthquake Public Awareness ConsultantDhaka - Bangladesh/Asia

Our Ref :ETASMI/SE-Mw 6.9-120sd/9-18-11 Radio Link International Email
09:32 AM Dhaka Time,Tuesday, September 20 + 6 Hours GMT

On Sun, 9/18/11, francis chacko <forum@sefindia.org> wrote:
[quote]
From: francis chacko <forum@sefindia.org>
Subject: [SEFI] Re: Sikkim Earthquake Sept 18 2001
To: general@sefindia.org
Date: Sunday, September 18, 2011, 10:21 PM

            A VERY GOOD IDEA.IN FACT AS MUCH DETAILS AS POSSIBLE INCLUDING PHOTOGRAPHS SHOULD BE COLLECTED. ENGINEERS NEAR BY LOCATIONS SHOULD TAKE INTEREST AND LET US BE KNOWN.

AS PROF. ARC INFORMED THE CAUSE FOR FAILURE OF MOBILE NET WORK MAY BE DUE TO THE COLLAPSE OF MOBILE TOWERS.

I AM AFRAID THAT THERE ARE MANY MOBILE TOWERS IN THE COUNTRY ERECTED ON THE EXISTING BUILDINGS WITH OUT HAVING PROPER STRUCTURAL ANALYSIS.

K C FRANCIS



On Sun, Sep 18, 2011 at 9:58 PM, alpa_sheth forum@sefindia.org)> wrote:
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