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sriprakash_shastry ...
Joined: 23 Mar 2010 Posts: 50
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Posted: Thu Oct 17, 2013 3:38 am Post subject: Review of IS 875 Wind Code |
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Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash |
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bharatthej SEFI Member
Joined: 06 Jan 2011 Posts: 13
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Posted: Thu Oct 17, 2013 4:30 am Post subject: Review of IS 875 Wind Code |
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Rather better way would be just like American way we can go with zonal classification. As in, UBC Vol. 2 (i use the same) for such cases with the estimated max speed from met dept records,
On Thu, Oct 17, 2013 at 9:08 AM, sriprakash_shastry <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash
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K B NEELAKANTAN SEFI Member
Joined: 18 Mar 2010 Posts: 10
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Posted: Thu Oct 17, 2013 8:10 am Post subject: Review of IS 875 Wind Code |
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Yes. The wind speeds prescribed in IS Code needs revision to reflect the changing environment.
On Thu, Oct 17, 2013 at 9:08 AM, sriprakash_shastry <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash
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ishacon Silver Sponsor
Joined: 01 Apr 2008 Posts: 148
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Posted: Thu Oct 17, 2013 8:28 am Post subject: Review of IS 875 Wind Code |
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Dear All,
I am sure we structural consultants are absolutely dismayed at
BIS for not issuing a revised IS 875 Part III for wind. WE had Tsunami and 2 cyclones
and yet no action is taken to issue ASAP revisions to this antique code.
I believe SERC Chennai had almost finalised the revision, though it lacked the
changes we all would have preferred the criteria for wind speeds and the
return period to have been line with revised British Code for Wind loads, which has now
been around for about 15 years.
Regards
V P AGARWAL
CONSULTANT,
ISHA CONSULTANTS (P) LTD
NEW DELHI 11 00 74
PH: 011-2630 1158; 080 100 717 49
Quote: | -- Original Message --
From: sriprakash_shastry (forum@sefindia.org)
To: general@sefindia.org (general@sefindia.org)
Sent: Thursday, October 17, 2013 9:08 AM
Subject: [SEFI] Review of IS 875 Wind Code
Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash
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orugantibhargavi SEFI Member
Joined: 21 Jul 2010 Posts: 3
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Posted: Thu Oct 17, 2013 8:52 am Post subject: Review of IS 875 Wind Code |
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Dear all,
These wind loads are major governing factors for a pre engineered buildings. Phenomenal change in the wind loads due to the natural typhoon need to be reviewed. It's very alarming and needs immediate attention.
RegardsUsha Bhargavi.oruganti
On 17-Oct-2013, at 9:08 AM, "sriprakash_shastry" <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash
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bsec Bronze Sponsor
Joined: 26 Jan 2003 Posts: 204
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Posted: Thu Oct 17, 2013 9:20 am Post subject: Review of IS 875 Wind Code |
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Dear All,
Civil Engineering structures are not always designed to remain safe against all calamities. Design loads are decided to ensure safety against routine loads and ensure minimal loss of life / property under severe loads (like that of EQ, Cyclones, Tsunamis ....etc.). I am sure the basic mean hourly design wind speed of 50 Km/hr in coastal belt at 10m height, duly takes into account the occasional cyclonic wind storms of 200 Km/hr. I am sure designing all the structures in coastal belt for 200 Km/hr wind will be far more costly than designing to allow certain limited failures for such cyclones, as and when it comes. It's a question of risk assessment.
I think an expert in Wind Loading formulation can explain it better.
Best Wishes
Alok Bhowmick
On Thu, Oct 17, 2013 at 2:02 PM, ishacon <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote] Dear All,
I am sure we structural consultants are absolutely dismayed at
BIS for not issuing a revised IS 875 Part III for wind. WE had Tsunami and 2 cyclones
and yet no action is taken to issue ASAP revisions to this antique code.
I believe SERC Chennai had almost finalised the revision, though it lacked the
changes we all would have preferred the criteria for wind speeds and the
return period to have been line with revised British Code for Wind loads, which has now
been around for about 15 years.
Regards
V P AGARWAL
CONSULTANT,
ISHA CONSULTANTS (P) LTD
NEW DELHI 11 00 74
PH: 011-2630 1158; 080 100 717 49
--auto removed--
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jatin_dce SEFI Member
Joined: 26 Mar 2011 Posts: 1
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Posted: Thu Oct 17, 2013 9:47 am Post subject: |
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I agree with honourable members' concern with regard to revision of Indian Wind Load Code in the aftermath of cyclone hitting the east coast.
But major projects such as Paradip refinery have used basic wind speed of 66m/s as against the codal speed of 50m/s.
Therefore, my point of submission is that till the time code is revised, project design basis must include the expected wind speed as based on climatic phenomena.
Client/PMC and engineering sub-contractor shall have to be proactive while finalizing the design basis for projects in such areas where codal limits do not reflect the ground situation.
Regards.
Jatin. |
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prithwishsaha2008@gmail.c SEFI Member
Joined: 20 Sep 2013 Posts: 1
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Posted: Thu Oct 17, 2013 10:24 am Post subject: Review of IS 875 Wind Code |
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Dear All,
What I feel is that basic wind speed should be revised and related with terrain category and height of the structure.What I mean is that for a particular area say for costal area of west bengal or orrisa, for low rise building basic wind speed may remain unaltered, but for a structures with a significant height, must be modified to some extent.It is also very important to revise the return period as mentioned by Mr. V P AGARWAL.
Regards,
*Prithwish Saha*
Assistant Engineer (STRUCTURE & SPECIAL PROJECTS).
Jacobs CES (I) Pvt. Ltd.
CES Centre,DM 3 & 4, Sector-5, Salt Lake City, Kolkata-700091.
*Prithwish Saha*
Assistant Engineer (STRUCTURE & SPECIAL PROJECTS).
Jacobs CES (I) Pvt. Ltd.
CES Centre,DM 3 & 4, Sector-5, Salt Lake City, Kolkata-700091.
On Thu, Oct 17, 2013 at 3:05 PM, bsec <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear All,
Civil Engineering structures are not always designed to remain safe against all calamities. Design loads are decided to ensure safety against routine loads and ensure minimal loss of life / property under severe loads (like that of EQ, Cyclones, Tsunamis ....etc.). I am sure the basic mean hourly design wind speed of 50 Km/hr in coastal belt at 10m height, duly takes into account the occasional cyclonic wind storms of 200 Km/hr. I am sure designing all the structures in coastal belt for 200 Km/hr wind will be far more costly than designing to allow certain limited failures for such cyclones, as and when it comes. It's a question of risk assessment.
I think an expert in Wind Loading formulation can explain it better.
Best Wishes
Alok Bhowmick
On Thu, Oct 17, 2013 at 2:02 PM, ishacon forum@sefindia.org (forum@sefindia.org))> wrote:
Quote: | Dear All,
I am sure we structural consultants are absolutely dismayed at
BIS for not issuing a revised IS 875 Part III for wind. WE had Tsunami and 2 cyclones
and yet no action is taken to issue ASAP revisions to this antique code.
I believe SERC Chennai had almost finalised the revision, though it lacked the
changes we all would have preferred the criteria for wind speeds and the
return period to have been line with revised British Code for Wind loads, which has now
been around for about 15 years.
Regards
V P AGARWAL
CONSULTANT,
ISHA CONSULTANTS (P) LTD
NEW DELHI 11 00 74
PH: 011-2630 1158; 080 100 717 49
--auto removed--
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balki16 ...
Joined: 04 Nov 2012 Posts: 111
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Posted: Thu Oct 17, 2013 11:32 am Post subject: Re: Review of IS 875 Wind Code |
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sriprakash_shastry wrote: | Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash |
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Dr. N. Subramanian General Sponsor
Joined: 21 Feb 2008 Posts: 5538 Location: Gaithersburg, MD, U.S.A.
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Posted: Thu Oct 17, 2013 2:04 pm Post subject: Re: Review of IS 875 Wind Code |
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Dear Er Sripraksh,
Thanks for this imp. posting and question. For a long time I have been advocating for the revision of Wind Loads (see my earlier postings about this), as the global warming has resulted in increased wind speeds during cyclones. Moreover, the places which are not prone for such high wind speeds, are now being affected. There is an urgent need to change the wind speed map of India.
Best wishes,
NS
sriprakash_shastry wrote: | Dear All,
The recent cyclone phailin has broken the maximum basic wind speed prescribed by the code for the eastern coast of India which is 50 m/sec or 180 km/h. Phailin had wind speeds of 220 Km/hr. Similarly the cyclone of 1999 in Odisha which killed over 10,000 people also had wind speeds of about 280 km/hr.
As I write this post, typhoon Nari is devastating Vietnam and Thailand and Typhoon Wipha has killed over 20 people in Japan. These typhoons titled as once in a decade are becoming more common place. In the Indian context, the 50 year return period of massive storms seems to be diminishing and large storms are now bombarding the Indian shores more often.
Having said this. I would like to pose the question "Is it time to increase our basic wind speeds and also to review our wind code in it's entirety." I would like to have the thoughts of experts on this forum with regard to this topic.
Regards
Sriprakash |
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