View previous topic :: View next topic |
Author |
Message |
uhvaryani General Sponsor
Joined: 21 May 2008 Posts: 258
|
Posted: Thu Jan 23, 2020 7:30 am Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
Posted via Email |
|
Back to top |
|
|
RAMARAJ S SEFI Member
Joined: 17 May 2017 Posts: 3
|
Posted: Thu Jan 23, 2020 9:30 am Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Dear Uhvaryani, What is the condition of Tank, I mean fully filled or partially or empty? What is the dimension of Tank? If you have any structural drawing, Kindly produce for analysis
On Thu, 23 Jan 2020 at 14:28, uhvaryani <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
|
Posted via Email |
|
Back to top |
|
|
vivek_agrawal SEFI Member
Joined: 24 Jun 2016 Posts: 4
|
Posted: Thu Jan 23, 2020 9:50 am Post subject: |
|
|
it seams, lap length / curtailment of reinforcement / staggering of lap failure which resulted in buckling failure |
|
Back to top |
|
|
sangeeta_wij ...
Joined: 21 Apr 2016 Posts: 59
|
Posted: Thu Jan 23, 2020 10:30 am Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Yes, local buckling could be a reason, and it will be helpful to know the diameter of the shaft as well as the size/shape of the top .In any case, 1893 Code for Tank design has changed quite drastically, and it will be nice to carry out a check of all existing elevated staging tanks based on that.
Best Regards
Sangeeta Wij
President,WISE India
Managing Partner
SD Engineering Consultants LLP
Vice President(North),Indian Association of Structural Engineers,
Fellow and Chartered Engineer, Institution of Engineers
H333 New Rajinder Nagar(Lower Ground Floor),
New Delhi-110060
Ph:9811776210;01145128530
From: uhvaryani [mailto:forum@sefindia.org]
Sent: 23 January 2020 14:26
To: general@sefindia.org
Subject: [SEFI] Failure of overhead water tank,at BANKURA,WEST BENGAL
Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
Posted via Email |
|
Back to top |
|
|
indutridibesh SEFI Member
Joined: 25 Mar 2011 Posts: 12
|
Posted: Thu Jan 23, 2020 12:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Here is a link to the complete videohttps://youtu.be/vUEhqlBTCqo
The circumferential crack in the shaft is clearly visible from some time ahead of collapse. The crack might be due to inadequate reinforcement and/or weak joint in concrete as well.
If the shaft wall is thin enough in proportion to its diameter, then the wall would wobble and it may fail when there is bending of the shaft.
On Thu, 23 Jan, 2020, 14:27 uhvaryani, <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
|
Posted via Email |
|
Back to top |
|
|
vgrelan SEFI Member
Joined: 22 Jul 2015 Posts: 5
|
Posted: Thu Jan 23, 2020 2:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
What was the unsupported length of the shaft?
On Thu, 23 Jan, 2020, 4:26 PM sangeeta_wij, <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote: | Yes, local buckling could be a reason, and it will be helpful to know the diameter of the shaft as well as the size/shape of the top .In any case, 1893 Code for Tank design has changed quite drastically, and it will be nice to carry out a check of all existing elevated staging tanks based on that.
Best Regards
Sangeeta Wij
President,WISE India
Managing Partner
SD Engineering Consultants LLP
Vice President(North),Indian Association of Structural Engineers,
Fellow and Chartered Engineer, Institution of Engineers
H333 New Rajinder Nagar(Lower Ground Floor),
New Delhi-110060
Ph:9811776210;01145128530
From: uhvaryani [mailto:forum@sefindia.org (forum@sefindia.org)]
Sent: 23 January 2020 14:26
To: general@sefindia.org (general@sefindia.org)
Subject: [SEFI] Failure of overhead water tank,at BANKURA,WEST BENGAL
Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
|
Posted via Email |
|
Back to top |
|
|
janak_436 SEFI Member
Joined: 02 Jan 2020 Posts: 1
|
Posted: Thu Jan 23, 2020 2:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Sir/mam can you send me please full etabs course in pdf format?
On 23 Jan 2020 6:25 p.m., "sangeeta_wij" <forum@sefindia.org (forum@sefindia.org)> wrote: Quote: | Yes, local buckling could be a reason, and it will be helpful to know the diameter of the shaft as well as the size/shape of the top .In any case, 1893 Code for Tank design has changed quite drastically, and it will be nice to carry out a check of all existing elevated staging tanks based on that.
Best Regards
Sangeeta Wij
President,WISE India
Managing Partner
SD Engineering Consultants LLP
Vice President(North),Indian Association of Structural Engineers,
Fellow and Chartered Engineer, Institution of Engineers
H333 New Rajinder Nagar(Lower Ground Floor),
New Delhi-110060
Ph:9811776210;01145128530
From: uhvaryani [mailto:forum@sefindia.org (forum@sefindia.org)]
Sent: 23 January 2020 14:26
To: general@sefindia.org (general@sefindia.org)
Subject: [SEFI] Failure of overhead water tank,at BANKURA,WEST BENGAL
Dear Sefians, Recently,a failure of an overhead water tank,supported on a reinforced concrete shaft of 150 mm thickness and of height 7.5 m has been reported in the media.
The shaft broke at about mid-height.What could be the reason of this failure?
Earlier cases of failure of these structures showed sinking of the shaft in the ground.In the present case soil is reported to be good, so the shaft has broken into two parts.I request our senior members to consider this case and give us the reason of this failure.My view is that the shaft thickness of 150mm is in sufficient and this has caused local buckling of the shaft.
with best wishes and regards,
uhvaryani
|
Posted via Email |
|
Back to top |
|
|
aknargotra SEFI Member
Joined: 28 Jan 2011 Posts: 3
|
Posted: Thu Jan 23, 2020 6:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Dear Sefians
Height appears to be much more than 7.5 m. Compare with building height. This was waiting to happen since there was a big circumferential crack. Exact reasons can be analysed once full particulars of structure including history of crack is known.With regards,
Ajay Kumar
On Thu 23 Jan, 2020, 10:56 PM indutridibesh, <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote] Here is a link to the complete videohttps://youtu.be/vUEhqlBTCqo
The circumferential crack in the shaft is clearly visible from some time ahead of collapse. The crack might be due to inadequate reinforcement and/or weak joint in concrete as well.
If the shaft wall is thin enough in proportion to its diameter, then the wall would wobble and it may fail when there is bending of the shaft.
On Thu, 23 Jan, 2020, 14:27 uhvaryani, forum@sefindia.org (forum@sefindia.org))> wrote:
--auto removed--
Posted via Email |
|
Back to top |
|
|
James_Cohen SEFI Regulars
Joined: 26 Jan 2003 Posts: 32
|
Posted: Thu Jan 23, 2020 6:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
The video suggests loss of strength at the point of failure. There is no tilting, the failure is circumferential and the collapse is primarily vertical. The mode of failure therefore appears to be crushing or hoop failure. Loss of strength is most likely due to longterm corrosion.
From: RAMARAJ S <forum@sefindia.org>
Sent: Thursday, January 23, 2020 12:39 PM
To: general@sefindia.org
Subject: [SEFI] Re: Failure of overhead water tank,at BANKURA,WEST BENGAL
Dear Uhvaryani, What is the condition of Tank, I mean fully filled or partially or empty? What is the dimension of Tank? If you have any structural drawing, Kindly produce for analysis
On Thu, 23 Jan 2020 at 14:28, uhvaryani forum@sefindia.org (forum@sefindia.org))> wrote:
--auto removed--
Posted via Email |
|
Back to top |
|
|
Bijoy Chandra Tripathy SEFI Member
Joined: 28 May 2011 Posts: 9
|
Posted: Thu Jan 23, 2020 6:30 pm Post subject: Failure of overhead water tank,at BANKURA,WEST BENGAL |
|
|
Dear Sefians,It reminds of the failure of OHT in Dhenkanal,Odisha in the early 80s.Among the causes 'bad' concreting and lack and deficient structural details eg lap locations and lap details were said to be the critical ones.Government had not gone for detailed technical investigation.Valuable data got buried.
In the present case the TV footage indicates collapse of the RCC shaft at a particular height /zone.It is quite possible that improper placing and compaction of concrete in the thin section of 150mm(?) coupled with lack of continuous curing both inside and outside might be original culprit!However detailed investigation to the causes of failure must be instituted by WB Government in the national interest.
With regards
Er B C Tripathy
On Thu, 23 Jan 2020, 23:09 RAMARAJ S, <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote] Dear Uhvaryani, What is the condition of Tank, I mean fully filled or partially or empty? What is the dimension of Tank? If you have any structural drawing, Kindly produce for analysis
On Thu, 23 Jan 2020 at 14:28, uhvaryani forum@sefindia.org (forum@sefindia.org))> wrote:
--auto removed--
Posted via Email |
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You can download files in this forum
|
|
|