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amitavabh SEFI Member
Joined: 26 Jan 2003 Posts: 18
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Posted: Wed Sep 26, 2007 1:17 amPost subject: Spreadsheets from members |
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Dear Friends,
I would like to draw attention of our forum members. I have seen that now-a-days nobody is contributing their spreadsheets/programs to our SEFI forum.
这是个不健康的论坛。我请求每个body to upload their spreadsheet/programs to this site and enrich it. The members may arrange some "spreadsheet drive month" for this.
Please let me know your comments.
Regards Amitava Bhattacharjee Kolkata, India.
wrote: ------------------------- Message From a_bhattacharjee[AT]yah... Subject: Daily Digest Fri Sep 14 00:00:05 2007 Date: 14/09/07 Time: 10:57:24 ------------------------- Dear Bhavin,
Thank you for your mail. I have some items to discuss further, which are as following.
1. Support: I prefer spring support at nodes of base raft plate elements.
2. During Uplift pressure:
a) To know Stability against uplift a simple hand calculation may be used and at that time effect of spring support shall not be taken.
b) For uplift load case the local bending/forces of the base raft may be obtained from Staad using following idea:
Provide spring support around the edge of the raft, in line with the vertical tank walls to give a near site effect. Use proportionate influence area of raft to calculate each spring support.
When the base raft bends, it will mainly bend within its periphery beneath the heavy walls.
3. Additional Load cases: I had discussed about the loadcases that one shall take to analyse underground tanks. However, another 2 load cases shall be taken into consideration for analysis of underground tanks. They are:
a) Dynamic increment of soil pressure during seismic activity. b) Sloushing effect of liquid inside the tank during the seismic activity. The liquid will change place during such movement like it does in rivers, ponds and Oceans during seismic activity.
However this kind of analysis is done for very important tank types. Say tanks that will contain radio active material, hazerdous liquids detrimental to underground and over ground environment etc.
Regards
wrote: ------------------------- Message From bhavinpatel[AT]vms... Subject: Underground Tank Design Date: 13/09/07 Time: 11:11:23 ------------------------- Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
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------------------------- Message From Akshaya.Das[AT]ake... Subject: Underground Tank Design Date: 14/09/07 Time: 12:14:07 ------------------------- Bhavin,
Reply to Point No.2
Use compression only spring to simulate soil. In case of uplift corresponding soil spring will be inactive and will show zero support reaction.
Regards,
Dr A K Das
-----Original Message----- Message From bhavinpatel[AT]vms... [mailto:bhavinpatel[AT]vms...] Sent: Thursday, September 13, 2007 4:41 PM To: Das, Akshaya Subject: Underground Tank Design
Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
Why delete messages? Unlimited storage is just a click away.
Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
Everywhere
This e-mail and any attachment are confidential and may be privileged or otherwise protected from disclosure. It is solely intended for the person(s) named above. If you are not the intended recipient, any reading, use, disclosure, copying or distribution of all or parts of this e-mail or associated attachments is strictly prohibited. If you are not an intended recipient, please notify the sender immediately by replying to this message or by telephone and delete this email and any attachments permanently from your system.
-------------------------
------------------------- Message From bhavinpatel[AT]vms... Subject: Underground Tank Design Date: 14/09/07 Time: 13:07:57 ------------------------- Dear Dr. A K Das,
I have already tried that option of using compression only spring. I gave uplift pressure in a separate load case and combine that in load combinations. Now when I analyzed the model, the uplift load will not be resisted by supports and hence it will give me large deformations causing instabilities. Those large deformations when combined in load combinations will give me very very large moments which is surely impractical. The other option is to apply uplift pressure and vertical downward loads in one load case. This option may be workable but again there are two issues. 1> For some load combinations we have to design the Structure/Raft for no water pressure from bottom. In such case it is difficult and confusing to define separate dead load case and analyze for that. 1> When there is a large raft with different size of panels, the no. of iterations required for converging the reactions are very large which cause very long time to analyze. I had analyzed such structure and it took 24 hours to analyze even at the initial stage.
So compression spring is the best option but with the above issues.
Regards, Bhavin Patel
-----Original Message----- Message From Akshaya.Das[AT]ake... [mailto:Akshaya.Das[AT]ake...]
Sent: 14 September 2007 17:44 To: Bhavin Patel Subject: Underground Tank Design
Bhavin,
Reply to Point No.2
Use compression only spring to simulate soil. In case of uplift corresponding soil spring will be inactive and will show zero support reaction.
Regards,
Dr A K Das
-----Original Message----- Message From bhavinpatel[AT]vms... [mailto:bhavinpatel[AT]vms...] Sent: Thursday, September 13, 2007 4:41 PM To: Das, Akshaya Subject: Underground Tank Design
Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
Why delete messages? Unlimited storage is just a click away.
Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
Everywhere
This e-mail and any attachment are confidential and may be privileged or otherwise protected from disclosure. It is solely intended for the person(s) named above. If you are not the intended recipient, any reading, use, disclosure, copying or distribution of all or parts of this e-mail or associated attachments is strictly prohibited. If you are not an intended recipient, please notify the sender immediately by replying to this message or by telephone and delete this email and any attachments permanently from your system.
-------------------------
是一个更好的柔情。获得更好的关系swers from someone who knows. Yahoo! Answers - Check it out.
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er.bhavin SEFI Member
Joined: 26 Jan 2003 Posts: 5
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Posted: Wed Sep 26, 2007 6:05 amPost subject: Spreadsheets from members |
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Dear sir,
I appreciate your appeal. I am preparing an excel sheet which gives the column design results calculated in staad to excel with column no., Area of steel required & Area of concrete required. I hope this may be helpful. As it prepares I will upload for your invaluable comments.
Another thing that I want to discuss with all members is Staad Design Parameters. Most of the Indian people are using staad for analysis. Some are using analysis results and design the elements manually. But as we know we can also design the elements with using staad if we use proper 德sign parameters. There are Lots of design parameters available in STAAD. So I think we must discuss them in this forum. And Check the 德sign made in STAAD with manual design. STAAD design will save lots of engineering hours.
Thanks. Bhavin
-----Original Message----- Message From a_bhattacharjee[AT]yah... [mailto:a_bhattacharjee[AT]yah...] Sent: 26 September 2007 12:17 To: Bhavin Patel Subject: Spreadsheets from members
Dear Friends,
I would like to draw attention of our forum members. I have seen that now-a-days nobody is contributing their spreadsheets/programs to our SEFI forum.
这是个不健康的论坛。我请求每个body to upload their spreadsheet/programs to this site and enrich it. The members may arrange some "spreadsheet drive month" for this.
Please let me know your comments.
Regards Amitava Bhattacharjee Kolkata, India.
wrote: ------------------------- Message From a_bhattacharjee[AT]yah... Subject: Daily Digest Fri Sep 14 00:00:05 2007 Date: 14/09/07 Time: 10:57:24 ------------------------- Dear Bhavin,
Thank you for your mail. I have some items to discuss further, which are as following.
1. Support: I prefer spring support at nodes of base raft plate elements.
2. During Uplift pressure:
a) To know Stability against uplift a simple hand calculation may be used and at that time effect of spring support shall not be taken.
b) For uplift load case the local bending/forces of the base raft may be obtained from Staad using following idea:
Provide spring support around the edge of the raft, in line with the vertical tank walls to give a near site effect. Use proportionate influence area of raft to calculate each spring support.
When the base raft bends, it will mainly bend within its periphery beneath the heavy walls.
3. Additional Load cases: I had discussed about the loadcases that one shall take to analyse underground tanks. However, another 2 load cases shall be taken into consideration for analysis of underground tanks. They are:
a) Dynamic increment of soil pressure during seismic activity. b) Sloushing effect of liquid inside the tank during the seismic activity. The liquid will change place during such movement like it does in rivers, ponds and Oceans during seismic activity.
However this kind of analysis is done for very important tank types. Say tanks that will contain radio active material, hazerdous liquids 德trimental to underground and over ground environment etc.
Regards
wrote: ------------------------- Message From bhavinpatel[AT]vms... Subject: Underground Tank Design Date: 13/09/07 Time: 11:11:23 ------------------------- Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
Why delete messages? Unlimited storage is just a click away.
Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
-------------------------
Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. -------------------------
------------------------- Message From Akshaya.Das[AT]ake... Subject: Underground Tank Design Date: 14/09/07 Time: 12:14:07 ------------------------- Bhavin,
Reply to Point No.2
Use compression only spring to simulate soil. In case of uplift corresponding soil spring will be inactive and will show zero support reaction.
Regards,
Dr A K Das
-----Original Message----- Message From bhavinpatel[AT]vms... [mailto:bhavinpatel[AT]vms...] Sent: Thursday, September 13, 2007 4:41 PM To: Das, Akshaya Subject: Underground Tank Design
Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
Why delete messages? Unlimited storage is just a click away.
Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
Everywhere
This e-mail and any attachment are confidential and may be privileged or otherwise protected from disclosure. It is solely intended for the person(s) named above. If you are not the intended recipient, any reading, use, disclosure, copying or distribution of all or parts of this e-mail or associated attachments is strictly prohibited. If you are not an intended recipient, please notify the sender immediately by replying to this message or by telephone and delete this email and any attachments permanently from your system.
-------------------------
------------------------- Message From bhavinpatel[AT]vms... 主题:Re: [SEFI]半岛软件下载 Underground Tank Design Date: 14/09/07 Time: 13:07:57 ------------------------- Dear Dr. A K Das,
I have already tried that option of using compression only spring. I gave uplift pressure in a separate load case and combine that in load combinations. Now when I analyzed the model, the uplift load will not be resisted by supports and hence it will give me large deformations causing instabilities. Those large deformations when combined in load combinations will give me very very large moments which is surely impractical. The other option is to apply uplift pressure and vertical downward loads in one load case. This option may be workable but again there are two issues. 1> For some load combinations we have to design the Structure/Raft for no water pressure from bottom. In such case it is difficult and confusing to define separate dead load case and analyze for that. 1> When there is a large raft with different size of panels, the no. of iterations required for converging the reactions are very large which cause very long time to analyze. I had analyzed such structure and it took 24 hours to analyze even at the initial stage.
So compression spring is the best option but with the above issues.
Regards, Bhavin Patel
-----Original Message----- Message From Akshaya.Das[AT]ake... [mailto:Akshaya.Das[AT]ake...]
Sent: 14 September 2007 17:44 To: Bhavin Patel Subject: Underground Tank Design
Bhavin,
Reply to Point No.2
Use compression only spring to simulate soil. In case of uplift corresponding soil spring will be inactive and will show zero support reaction.
Regards,
Dr A K Das
-----Original Message----- Message From bhavinpatel[AT]vms... [mailto:bhavinpatel[AT]vms...] Sent: Thursday, September 13, 2007 4:41 PM To: Das, Akshaya Subject: Underground Tank Design
Dear Mr.Bhattacharjee,
When we model Base raft in STAAD, there are two issues regarding supports. 1. Which kind of support should we provide. Plate Mat Elastic Mat Spring Support. (I personally feel the plate mat option gives better results when raft is modeled with plate element.) 2. When central portion of base raft is subjected to uplift pressure in tank is empty condition, The spring support will resist that upward deflection according to their stiffness which is not the actual case with soil.
Regards Bhavin _________
a_bhattacharjee[AT]yah... wrote: Dear Jagjit,
For designing underground tanks you can use following methods:
1. Use plate element and model it in Staad or other software. Provide soil spring support for base raft.
Calculate soil, water and surcharge pressure on wall. Calculate uplift due to water on raft. Use tank empty + soil around tank present condition. Then use full + soil absent around tank during test condition for worst load cases. If there is chember in the tanks then use alternate chember filled/empty etc. Then analyse.
Take output forces of plates. Select maximum force of "plate center stress summery" among the plates of each wall. Add torsional moment to the moment of both direction seperately. Then Design for this moment of each wall. Then take out bottom and top slabs. Calculate and check the crack width of walls/slabs against code values.
Use IS 3370 and IS 456 for refering to codal provision.
2. Calculate forces on tanks as told above. then use Roark's table to find out moment coefficients and then design for those forces. Check crack width.
Regards Amitava Bhattacharjee Kolkata
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
Why delete messages? Unlimited storage is just a click away.
Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
Everywhere
This e-mail and any attachment are confidential and may be privileged or otherwise protected from disclosure. It is solely intended for the person(s) named above. If you are not the intended recipient, any reading, use, disclosure, copying or distribution of all or parts of this e-mail or associated attachments is strictly prohibited. If you are not an intended recipient, please notify the sender immediately by replying to this message or by telephone and delete this email and any attachments permanently from your system.
-------------------------
是一个更好的柔情。获得更好的关系swers from someone who knows. Yahoo! Answers - Check it out.
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Youcannotpost new topics in this forum Youcannotreply to topics in this forum Youcannotedit your posts in this forum Youcannot德lete your posts in this forum Youcannotvote in polls in this forum Youcanattach files in this forum Youcandownload files in this forum
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