Saturday, November 22, 2008

RE: Seismic code for Iraq

Gautam,

I don’t know how legal the website is….but here is a very good link with structural shapes and properties

http://www.sap2000.org/SECTIONS-2006-1-3-ES-EN-IT.htm

 

Or an alternate link on ArcelorMittal

http://www.constructalia.com/en_EN/products/productos_detalle.jsp?idApli=231196

 

HTH,

Anantha

 

From: Gautam Manandhar [mailto:Gautam_Manandhar@ci.richmond.ca.us]
Sent: Friday, November 21, 2008 8:13 PM
To: seaint@seaint.org
Subject: RE: Seismic code for Iraq

 

Alex:

 

Thanks for your response.

 

Gautam, SE

 


From: Alexander Bausk [mailto:bauskas@gmail.com]
Sent: Friday, November 21, 2008 3:13 PM
To: seaint@seaint.org
Subject: Re: Seismic code for Iraq

 

On Sat, Nov 22, 2008 at 12:50 AM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Check with this Frelok catalogue:

http://www.frelok.ee/products_eng.pdf

It has detailed IPE sections description on page 33, and HEA sections on page 34.

Regards,
Alex.

--

Alexander Bausk
CAD manager, Structural engineer at
Nuclear Engineering&Research Lab
Dnipropetrovsk, Ukraine

Friday, November 21, 2008

RE: Seismic code for Iraq

Alex:

 

Thanks for your response.

 

Gautam, SE

 


From: Alexander Bausk [mailto:bauskas@gmail.com]
Sent: Friday, November 21, 2008 3:13 PM
To: seaint@seaint.org
Subject: Re: Seismic code for Iraq

 

On Sat, Nov 22, 2008 at 12:50 AM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Check with this Frelok catalogue:

http://www.frelok.ee/products_eng.pdf

It has detailed IPE sections description on page 33, and HEA sections on page 34.

Regards,
Alex.

--

Alexander Bausk
CAD manager, Structural engineer at
Nuclear Engineering&Research Lab
Dnipropetrovsk, Ukraine

RE: Seismic code for Iraq

David:

 

Thank you for your response.  The UFC manual gives Ss and S1 on Table D-2 for Baghdad and Basra – the project is in Baghdad.  At least, that is a start.

 

Gautam

 


From: David Topete [mailto:d.topete73@gmail.com]
Sent: Friday, November 21, 2008 3:18 PM
To: seaint@seaint.org
Subject: Re: Seismic code for Iraq

 

but they don't show anythign for iraq...  great...  sorry.  Good luck, gautam.

On Fri, Nov 21, 2008 at 3:16 PM, David Topete <d.topete73@gmail.com> wrote:

it's UFC 3-310-01

 

On Fri, Nov 21, 2008 at 3:15 PM, David Topete <d.topete73@gmail.com> wrote:

There is a UFC document listing seismic and wind criteria for global military installations.  I Believe it is UFC 3-310-00.  Search http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4,

 

On Fri, Nov 21, 2008 at 2:50 PM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

List Members:

 

I have been approached to provide structural design service for a project in Iraq.  I am looking for some info on lateral design requirements.  I presume the US Army would have some sort of design manual for Iraq.  Is anybody aware of one – I would appreciate a web link to such a document.

 

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Gautam

 



--
David Topete, SE



--
David Topete, SE




--
David Topete, SE

Progressive collapse

 
Dear list members,
 

I have a simple question. Any suggestion about the best software to perform a progressive collapse analysis? The structure is a architectural stylish high rise building with all the irregularities you can imagine.
 
Thank you for advise.



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Re: Seismic code for Iraq

but they don't show anythign for iraq...  great...  sorry.  Good luck, gautam.

On Fri, Nov 21, 2008 at 3:16 PM, David Topete <d.topete73@gmail.com> wrote:
it's UFC 3-310-01


On Fri, Nov 21, 2008 at 3:15 PM, David Topete <d.topete73@gmail.com> wrote:
There is a UFC document listing seismic and wind criteria for global military installations.  I Believe it is UFC 3-310-00.  Search http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4,


On Fri, Nov 21, 2008 at 2:50 PM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

List Members:

 

I have been approached to provide structural design service for a project in Iraq.  I am looking for some info on lateral design requirements.  I presume the US Army would have some sort of design manual for Iraq.  Is anybody aware of one – I would appreciate a web link to such a document.

 

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Gautam

 




--
David Topete, SE



--
David Topete, SE



--
David Topete, SE

Re: Seismic code for Iraq

it's UFC 3-310-01

On Fri, Nov 21, 2008 at 3:15 PM, David Topete <d.topete73@gmail.com> wrote:
There is a UFC document listing seismic and wind criteria for global military installations.  I Believe it is UFC 3-310-00.  Search http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4,


On Fri, Nov 21, 2008 at 2:50 PM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

List Members:

 

I have been approached to provide structural design service for a project in Iraq.  I am looking for some info on lateral design requirements.  I presume the US Army would have some sort of design manual for Iraq.  Is anybody aware of one – I would appreciate a web link to such a document.

 

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Gautam

 




--
David Topete, SE



--
David Topete, SE

Re: Seismic code for Iraq

There is a UFC document listing seismic and wind criteria for global military installations.  I Believe it is UFC 3-310-00.  Search http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4,

On Fri, Nov 21, 2008 at 2:50 PM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

List Members:

 

I have been approached to provide structural design service for a project in Iraq.  I am looking for some info on lateral design requirements.  I presume the US Army would have some sort of design manual for Iraq.  Is anybody aware of one – I would appreciate a web link to such a document.

 

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Gautam

 




--
David Topete, SE

Re: Seismic code for Iraq

On Sat, Nov 22, 2008 at 12:50 AM, Gautam Manandhar <Gautam_Manandhar@ci.richmond.ca.us> wrote:

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Check with this Frelok catalogue:

http://www.frelok.ee/products_eng.pdf

It has detailed IPE sections description on page 33, and HEA sections on page 34.

Regards,
Alex.

--

Alexander Bausk
CAD manager, Structural engineer at
Nuclear Engineering&Research Lab
Dnipropetrovsk, Ukraine

RE: Seismic code for Iraq

List Members:

 

I have been approached to provide structural design service for a project in Iraq.  I am looking for some info on lateral design requirements.  I presume the US Army would have some sort of design manual for Iraq.  Is anybody aware of one – I would appreciate a web link to such a document.

 

Does anyone have access to the wide flange steel beam section properties – the drawings call for HEA240, HEA300, and IPE360.  I believe these conform to European standards.

 

Gautam

 

RE: doubler plates

Andrew,

Thanks for the reply.  I was aware of that program, however, The architectural considerations are limiting me on column size.  The cost doesn’t seem to be an issue with them on this matter.

Joe

 

From: Andrew Kester, P.E. [mailto:akester@cfl.rr.com]
Sent: Wednesday, November 19, 2008 9:54 AM
To: seaint@seaint.org
Subject: re: doubler plates

 

Joe,

Though I have not used it yet, AISC has a program on their website called “Clean Column” and it is a free Excel program for determining what size column you will need without stiffeners or doubler plates.  Per a Modern Steel Con. Article from Oct 07, the average floor column with 4 stiffeners equals about 1900lb of steel in equivalent labor costs. I am sure this depends on the price of the steel also, but steel had dropped considerably recently so more steel would be even more economic than adding stiffeners.

 

I have no idea of your situation, forces and stresses- just a suggestion.

 

Regards,

Andrew Kester, PE

Orlando, FL

 

 

 

Thursday, November 20, 2008

RE: Upward load on slabs per UFC 4-023-03

There is no good research for the millisecond blast load bracing dynamic effects in bending.  Intuitively it should not be a problem, but again it can not be quantified or computationally substantiated.  Most engineers will increase the section as opposed to adding bracing.  Increasing the section is cheaper.  Blast loading and uplift and progressive collapse studies are not that well understood at this time. 
 
There is research being conducted on wall assemblies with brick facade.  The brick mass absorbs a lot of energy, but it can not be quantified at this time to reduce superstructure blast loads.  The brick veneer is currently assumed sacrificial and has no special blast requirements. 

Regards, Harold Sprague






Subject: Upward load on slabs per UFC 4-023-03
Date: Thu, 20 Nov 2008 14:42:43 -0500
From: dwatt@rubyusa.com
To: seaint@seaint.org


I am working on a Corps of Engineers project that is required to resist progressive collapse. The project is a "Low Level of Protection" building that meets all setback requirements. I am unclear on how to interpret UFC 4-023-03 section 2-2.2 "Upward Loads on Floors and Slabs". It states "In each bay and at all floors and the roof, the slab/floor system must be able to withstand a net upward load of a magnitude 1.0D+0.5L." It goes on to say "Design the floor system in each bay and its connections to the beams, girders, columns, capitals, etc to carry this load."

 

In the case of steel beams supporting concrete on metal deck I assume the concretes slab on metal deck will need to be designed for that upward pressure as well as its connection to the supporting structure. Where I am unclear is, are the floor beams required to be designed for the upward load applied to their tributary area with the bottom flange un-braced? If so, is bottom flange bridging typical provided to if reduce the beam section. Or does the upward load requirement only apply to the slab and its connections and not to the beams?

 

Also, is brick veneer on metal stud backup an allowable exterior wall construction for this type of project? All of the research I have found so far addresses the building structure and not so much the building envelope. Are there any special requirements to using brick veneer on metal stud for exterior walls on this type of project?

 

David M. Watt

 



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RE: OCBF Requirements

The metal building people got nailed on that one for no good reason.  They had to put in the exception to allow tension only to keep all of the thousands of metal buildings standing.  It was one of those code developer oops moments. 

Regards, Harold Sprague




Date: Thu, 20 Nov 2008 20:36:29 -0500
From: gtg740p@gmail.com
To: seaint@seaint.org
Subject: Re: OCBF Requirements

I remember reading you can use tension only now but I am not sure about a line of resistance that has a compression only diagonal. I am not sure I would want to do that anyway. But it may still be allowed by AISC, I am not sure.
 
Will H

On Thu, Nov 20, 2008 at 8:20 PM, Yousefi, Ben <Ben.Yousefi@mountainview.gov> wrote:
That is only a requirement for SCBF's (see section 13.2c of AISC 341). For OCBF's it is not an issue.
 

Ben Yousefi, SE, CBO
Chief Building Official
City of Mountain View, CA
(650) 526-7007
ben.yousefi@mountainview.gov


From: Larry Hauer [mailto:lhauer@live.com]
Sent: Thursday, November 20, 2008 5:10 PM
To: Struct. Eng. Assoc.
Subject: OCBF Requirements

 

I am designing a small one story steel framed processing facility using an R=3.25 for OCBF's and a Seismic Design Catagory E due to the S sub1 being high. The IBC/CBC references the AISC 341 for designing OCBF's which gives requirements for "V" and inverted "V" type bracing, but doesn't mention single bracing. The design example in the AISC Seismic Design manual for OCBF's is a single diagonal brace between 2 columns.
 
My question is: Is it permissible to use a single diagonal brace for a line of resistance, which would act either in tensiion or compression to resist seismic forces? I remember something in the '97 UBC about you couldn't use "tension only" bracing, (with some exceptions), but can't find any restrictions in the CBC/IBC, AISC, ASCE, etc., other than the fact that the referenced AISC 341 doesn't mention them.
 
Thanks in advance,
 
Larry Hauer, S.E.


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Re: OCBF Requirements

I remember reading you can use tension only now but I am not sure about a line of resistance that has a compression only diagonal. I am not sure I would want to do that anyway. But it may still be allowed by AISC, I am not sure.
 
Will H

On Thu, Nov 20, 2008 at 8:20 PM, Yousefi, Ben <Ben.Yousefi@mountainview.gov> wrote:

That is only a requirement for SCBF's (see section 13.2c of AISC 341). For OCBF's it is not an issue.

 

Ben Yousefi, SE, CBO
Chief Building Official
City of Mountain View, CA
(650) 526-7007
ben.yousefi@mountainview.gov


From: Larry Hauer [mailto:lhauer@live.com]
Sent: Thursday, November 20, 2008 5:10 PM
To: Struct. Eng. Assoc.
Subject: OCBF Requirements

 

I am designing a small one story steel framed processing facility using an R=3.25 for OCBF's and a Seismic Design Catagory E due to the S sub1 being high. The IBC/CBC references the AISC 341 for designing OCBF's which gives requirements for "V" and inverted "V" type bracing, but doesn't mention single bracing. The design example in the AISC Seismic Design manual for OCBF's is a single diagonal brace between 2 columns.
 
My question is: Is it permissible to use a single diagonal brace for a line of resistance, which would act either in tensiion or compression to resist seismic forces? I remember something in the '97 UBC about you couldn't use "tension only" bracing, (with some exceptions), but can't find any restrictions in the CBC/IBC, AISC, ASCE, etc., other than the fact that the referenced AISC 341 doesn't mention them.
 
Thanks in advance,
 
Larry Hauer, S.E.


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RE: OCBF Requirements

That is only a requirement for SCBF’s (see section 13.2c of AISC 341). For OCBF’s it is not an issue.

 

Ben Yousefi, SE, CBO
Chief Building Official
City of Mountain View, CA
(650) 526-7007
ben.yousefi@mountainview.gov


From: Larry Hauer [mailto:lhauer@live.com]
Sent: Thursday, November 20, 2008 5:10 PM
To: Struct. Eng. Assoc.
Subject: OCBF Requirements

 

I am designing a small one story steel framed processing facility using an R=3.25 for OCBF's and a Seismic Design Catagory E due to the S sub1 being high. The IBC/CBC references the AISC 341 for designing OCBF's which gives requirements for "V" and inverted "V" type bracing, but doesn't mention single bracing. The design example in the AISC Seismic Design manual for OCBF's is a single diagonal brace between 2 columns.
 
My question is: Is it permissible to use a single diagonal brace for a line of resistance, which would act either in tensiion or compression to resist seismic forces? I remember something in the '97 UBC about you couldn't use "tension only" bracing, (with some exceptions), but can't find any restrictions in the CBC/IBC, AISC, ASCE, etc., other than the fact that the referenced AISC 341 doesn't mention them.
 
Thanks in advance,
 
Larry Hauer, S.E.


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OCBF Requirements

I am designing a small one story steel framed processing facility using an R=3.25 for OCBF's and a Seismic Design Catagory E due to the S sub1 being high. The IBC/CBC references the AISC 341 for designing OCBF's which gives requirements for "V" and inverted "V" type bracing, but doesn't mention single bracing. The design example in the AISC Seismic Design manual for OCBF's is a single diagonal brace between 2 columns.
 
My question is: Is it permissible to use a single diagonal brace for a line of resistance, which would act either in tensiion or compression to resist seismic forces? I remember something in the '97 UBC about you couldn't use "tension only" bracing, (with some exceptions), but can't find any restrictions in the CBC/IBC, AISC, ASCE, etc., other than the fact that the referenced AISC 341 doesn't mention them.
 
Thanks in advance,
 
Larry Hauer, S.E.


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Re: Upward load on slabs per UFC 4-023-03

I am new to blast and it is a real pain.
 
This might be of some help, there begins an outline of some beam checks on page 36. Good luck.
 
 
On Thu, Nov 20, 2008 at 2:42 PM, David Watt <dwatt@rubyusa.com> wrote:

I am working on a Corps of Engineers project that is required to resist progressive collapse. The project is a "Low Level of Protection" building that meets all setback requirements. I am unclear on how to interpret UFC 4-023-03 section 2-2.2 "Upward Loads on Floors and Slabs". It states "In each bay and at all floors and the roof, the slab/floor system must be able to withstand a net upward load of a magnitude 1.0D+0.5L." It goes on to say "Design the floor system in each bay and its connections to the beams, girders, columns, capitals, etc to carry this load."

 

In the case of steel beams supporting concrete on metal deck I assume the concretes slab on metal deck will need to be designed for that upward pressure as well as its connection to the supporting structure. Where I am unclear is, are the floor beams required to be designed for the upward load applied to their tributary area with the bottom flange un-braced? If so, is bottom flange bridging typical provided to if reduce the beam section. Or does the upward load requirement only apply to the slab and its connections and not to the beams?

 

Also, is brick veneer on metal stud backup an allowable exterior wall construction for this type of project? All of the research I have found so far addresses the building structure and not so much the building envelope. Are there any special requirements to using brick veneer on metal stud for exterior walls on this type of project?

 

David M. Watt

 


RE: Upward load on slabs per UFC 4-023-03

David,

 

I can’t speak to the first question you posed, but I have done a Corps project with brick veneer over metal stud wall.  I can’t remember if there were any specific requirements in the UFC, but it was detailed with a 4” gap, which included 2” of rigid insulation and a 2” air gap.  HTH.

 

Doug Mayer, SE

 

From: David Watt [mailto:dwatt@rubyusa.com]
Sent: Thursday, November 20, 2008 11:43 AM
To: seaint@seaint.org
Subject: Upward load on slabs per UFC 4-023-03

 

I am working on a Corps of Engineers project that is required to resist progressive collapse. The project is a “Low Level of Protection” building that meets all setback requirements. I am unclear on how to interpret UFC 4-023-03 section 2-2.2 “Upward Loads on Floors and Slabs”. It states “In each bay and at all floors and the roof, the slab/floor system must be able to withstand a net upward load of a magnitude 1.0D+0.5L.” It goes on to say “Design the floor system in each bay and its connections to the beams, girders, columns, capitals, etc to carry this load.”

 

In the case of steel beams supporting concrete on metal deck I assume the concretes slab on metal deck will need to be designed for that upward pressure as well as its connection to the supporting structure. Where I am unclear is, are the floor beams required to be designed for the upward load applied to their tributary area with the bottom flange un-braced? If so, is bottom flange bridging typical provided to if reduce the beam section. Or does the upward load requirement only apply to the slab and its connections and not to the beams?

 

Also, is brick veneer on metal stud backup an allowable exterior wall construction for this type of project? All of the research I have found so far addresses the building structure and not so much the building envelope. Are there any special requirements to using brick veneer on metal stud for exterior walls on this type of project?

 

David M. Watt

 

Upward load on slabs per UFC 4-023-03

I am working on a Corps of Engineers project that is required to resist progressive collapse. The project is a “Low Level of Protection” building that meets all setback requirements. I am unclear on how to interpret UFC 4-023-03 section 2-2.2 “Upward Loads on Floors and Slabs”. It states “In each bay and at all floors and the roof, the slab/floor system must be able to withstand a net upward load of a magnitude 1.0D+0.5L.” It goes on to say “Design the floor system in each bay and its connections to the beams, girders, columns, capitals, etc to carry this load.”

 

In the case of steel beams supporting concrete on metal deck I assume the concretes slab on metal deck will need to be designed for that upward pressure as well as its connection to the supporting structure. Where I am unclear is, are the floor beams required to be designed for the upward load applied to their tributary area with the bottom flange un-braced? If so, is bottom flange bridging typical provided to if reduce the beam section. Or does the upward load requirement only apply to the slab and its connections and not to the beams?

 

Also, is brick veneer on metal stud backup an allowable exterior wall construction for this type of project? All of the research I have found so far addresses the building structure and not so much the building envelope. Are there any special requirements to using brick veneer on metal stud for exterior walls on this type of project?

 

David M. Watt

 

Re: Tall CMU Core Divider Wall

I thought it has to do with fireproofing but I will ask the architect to make sure it is needed.
 
thanks
 
WH

On Thu, Nov 20, 2008 at 1:51 PM, Paul Feather <PFeather@se-solutions.net> wrote:
William,
 
You can't look at a divider wall like this as an 85 foot wall, as you indicate the h/t would be absurd.
 
The wall should be designed to span horizontally for out of plane, and the entire core designed as the vertical element.  Just as the load over a window is really a triangle due to arching action in the masonry, the vertical load in the wall web will arch to the stiffening flanges (perpendicular walls).  You are basically designing a really tall tube.
 
The next hurdle is dealing with any lateral load.  A tube section like this is quite stiff.  You must include this in your lateral analysis, in which case the jambs will likely fail in compression, or you need to detail the wall specifically not to take lateral load (slip the slab connections with rubatex or a similar approach) and design for compatibility of deflection relative to the story drift.
 
The other question is why do you require this interior wall separator at all?  The entire elevator bank can be viewed as a single shaft, and steel beams at the floor lines can provide adequate lateral support for the elevator guide rails between cabs.
 
Paul Feather PE, SE
 
 


From: William Haynes [mailto:gtg740p@gmail.com]
Sent: Thursday, November 20, 2008 9:12 AM
To: seaint@seaint.org
Subject: Tall CMU Core Divider Wall

 
I have an 8" cmu elevator divider wall full height on the building. It is 85 feet tall (continuous) separating the 2 main cmu elevator shaft cores. It is about 8 feet in length and it ties into the cmu shaft walls at each end, and these end walls are tied into the concrete diaphragm.
 
Obviously, this wall does not have any horizontal diaphragm member coming in for support. I have it tied into the perpendicular cmu walls at each end with bond beams at 4'-0". There is the self weight on this wall and a 10 kip point load on the top from the elevator motor. SDC=C.
 
Does tieing it in this way only sound reasonable? The h/t for this wall is ridiculous. But, I can kind of see it just behaving as a series of bond beams (spaced 4'-0" vertically) spanning the 8 feet to the end walls, thereby carrying its own weight as a series of beams.
 
It just looks crazy in the architectural section shown as 85 feet freestanding. But this must be a common situation for a cmu or concrete divider wall in a high rise elevator shaft.
 
WH

RE: Tall CMU Core Divider Wall

William,
 
You can't look at a divider wall like this as an 85 foot wall, as you indicate the h/t would be absurd.
 
The wall should be designed to span horizontally for out of plane, and the entire core designed as the vertical element.  Just as the load over a window is really a triangle due to arching action in the masonry, the vertical load in the wall web will arch to the stiffening flanges (perpendicular walls).  You are basically designing a really tall tube.
 
The next hurdle is dealing with any lateral load.  A tube section like this is quite stiff.  You must include this in your lateral analysis, in which case the jambs will likely fail in compression, or you need to detail the wall specifically not to take lateral load (slip the slab connections with rubatex or a similar approach) and design for compatibility of deflection relative to the story drift.
 
The other question is why do you require this interior wall separator at all?  The entire elevator bank can be viewed as a single shaft, and steel beams at the floor lines can provide adequate lateral support for the elevator guide rails between cabs.
 
Paul Feather PE, SE
 
 


From: William Haynes [mailto:gtg740p@gmail.com]
Sent: Thursday, November 20, 2008 9:12 AM
To: seaint@seaint.org
Subject: Tall CMU Core Divider Wall

 
I have an 8" cmu elevator divider wall full height on the building. It is 85 feet tall (continuous) separating the 2 main cmu elevator shaft cores. It is about 8 feet in length and it ties into the cmu shaft walls at each end, and these end walls are tied into the concrete diaphragm.
 
Obviously, this wall does not have any horizontal diaphragm member coming in for support. I have it tied into the perpendicular cmu walls at each end with bond beams at 4'-0". There is the self weight on this wall and a 10 kip point load on the top from the elevator motor. SDC=C.
 
Does tieing it in this way only sound reasonable? The h/t for this wall is ridiculous. But, I can kind of see it just behaving as a series of bond beams (spaced 4'-0" vertically) spanning the 8 feet to the end walls, thereby carrying its own weight as a series of beams.
 
It just looks crazy in the architectural section shown as 85 feet freestanding. But this must be a common situation for a cmu or concrete divider wall in a high rise elevator shaft.
 
WH

Tall CMU Core Divider Wall

 
I have an 8" cmu elevator divider wall full height on the building. It is 85 feet tall (continuous) separating the 2 main cmu elevator shaft cores. It is about 8 feet in length and it ties into the cmu shaft walls at each end, and these end walls are tied into the concrete diaphragm.
 
Obviously, this wall does not have any horizontal diaphragm member coming in for support. I have it tied into the perpendicular cmu walls at each end with bond beams at 4'-0". There is the self weight on this wall and a 10 kip point load on the top from the elevator motor. SDC=C.
 
Does tieing it in this way only sound reasonable? The h/t for this wall is ridiculous. But, I can kind of see it just behaving as a series of bond beams (spaced 4'-0" vertically) spanning the 8 feet to the end walls, thereby carrying its own weight as a series of beams.
 
It just looks crazy in the architectural section shown as 85 feet freestanding. But this must be a common situation for a cmu or concrete divider wall in a high rise elevator shaft.
 
WH

RE: Concrete Bearing Pressure at Base Plates

The bearing pressure at the base plate to concrete interface is subject to the "maximum force" to offer a degree of assurance that the first mode of failure will be in bending in the steel frame.  That said, the compression stresses at the base plate interface are highly localized and if they are confined, should not drive the size of the pier.  There are many ways to control the stresses at the base plate interface including the use of a heavy setting template that can help distribute the compressive stresses into the concrete.  Also recall that if you are using grout, the grout is a much higher strength than the concrete. 

Regards, Harold Sprague




From: jrgrill@cableone.net
To: seaint@seaint.org
Subject: Concrete Bearing Pressure at Base Plates
Date: Tue, 18 Nov 2008 13:30:02 -0700

If you have a steel ordinary moment frame, that is designed for the maximum force that can be delivered, and the column base is fixed, is the bearing pressure at the base plate subject to the "maximum force…." ?  I'm getting some very large pier sizes using the "maximum force….", and I'm wondering if it is required.  I can't find any reference to this in the steel manual, the steel seismic manual or the ACI code.

Thanks,

Joe

 

Joseph R. Grill, PE

Verde Valley Engineering, PLLC

 



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RE: Expansion Joint in Building

I avoid expansion joints if at all possible.  But I calculate the anticipated thermal stresses in the structure.  Minimizing or eliminating expansion joints requires proper placement of lateral force resisting elements to allow thermal expansion with minimum constraint. 
 
Even if the superstructure requires expansion joints, I will generally allow the foundations to be constructed as continuous. 
 
The best source of information for expansion joints is:
http://books.nap.edu/catalog.php?record_id=9801
You do not have to order a hard copy.  You can read it on line for free and you can download a pdf. 

Regards, Harold Sprague






Date: Wed, 19 Nov 2008 18:25:58 -0800
From: engr_mondo@yahoo.com
Subject: Expansion Joint in Building
To: seaint@seaint.org



Hi,

Just wondering the requirements for expansion joints in building--in Saudi, they require a building (50m x 100m for instance) to provide expansion joints for every 50m in both horizontal dimensions. Please advice if it is needed to separate the building into two parts including the structure below the ground--grade/tie beams. I understand, that it is needed for thermal expansion. What does other do?

TIA,

Mondo



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Re: Flush Moment end plate connections

Hope this helps. I did a flush plate design(Top flg flush) recently by
telling the spread-sheet my beam was a W21" when it really was a 24". I
then put in a stiffener plate below the top flg to mimic the top flg of
a W21 with a a line of bolts between the stiffener and the W24 top flange.
Gary

Rand W Holtham wrote:
> Bill,
>
> I am in harmony with your rhetoric! But, Conrad's point is valid as well
> ...
>
> I use purchased software not for things I don't know or understand, but I
> use them to speed the process of do what it is I do know. A good software
> will be transparent. I typically use Descon and they show step by step each
> calculation so every aspect can be scrutinized.
>
> The flush plate analysis is a tedious time consuming process that is ripe
> for a spreadsheet. I don't need to learn how to calculate them I just need
> to do it faster and since I have need of one once every year or two, it is
> a toss up as to whether the time to write my own spread sheet (40hrs as
> Gerald said) or calc it by hand (say 2-4hrs)
>
> In particular the flush variety typically used in metal building systems is
> what I am looking for. Alex's corner is a great resource but his is the
> extended top and bottom symmetrical type.
>
> Thanks everyone for the input,
>
> Rand
>
>
>
>
> "Bill Allen"
> <t.w.allen@cox.ne
> t> To
> <seaint@seaint.org>
> 11/16/2008 12:41 cc
> PM
> Subject
> RE: Flush Moment end plate
> Please respond to connections
> <seaint@seaint.or
> g>
>
>
>
>
>
>
>
>
> Rand -
>
> Just curious, but if you bought a program, how would you know if it's
> accurate, without errors and contains the same engineering assumptions you
> would make? I guess you could compare the results of the output with a
> design you did in-house, but what if the answers are different? How would
> you determine if the differences are in engineering philosophy,
> interpretation of the code, a different level of conservatism than yours or
> just a flat out numerical error?
>
> I'm just askin'.
>
> T. William (Bill) Allen, S.E.
> ALLEN DESIGNS
> Consulting Structural Engineers
> V (949) 248-8588 . F(949) 209-2509
>
> -----Original Message-----
> From: Rand W Holtham [mailto:RHoltham@CBI.com]
> Sent: Friday, November 14, 2008 11:59 AM
> To: seaint@seaint.org
> Subject: Flush Moment end plate connections
>
>
> I was setting down to write a spreadsheet to do flush and extended multiple
> row moment end plate connections per AISC Design Guide #16. Is anyone aware
> of a commercially available spreadsheet that is available.
>
> TIA,
>
> Rand
>
>
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Wednesday, November 19, 2008

Re: Expansion Joint in Building

Hi Edmondo,

The local building code is, of course, your primary information source.
In our practice here, you don't need to slice the foundation at the expansion joint (note however that this doesn't hold for deformation joints).
In the national codes that I've looked through (CIS, Germany, Czechia), the requirements for expansion joints vary greatly (40m to >100m) depending on what type of structure you're designing, environment conditions etc. These are to be defined by calculation.

Regards,
Alex


On 11/20/08, edmondo san jose <engr_mondo@yahoo.com> wrote:

Hi,

Just wondering the requirements for expansion joints in building--in Saudi, they require a building (50m x 100m for instance) to provide expansion joints for every 50m in both horizontal dimensions. Please advice if it is needed to separate the building into two parts including the structure below the ground--grade/tie beams. I understand, that it is needed for thermal expansion. What does other do?

TIA,

Mondo




--
Alexander Bausk
CAD manager, Structural engineer at
Nuclear Engineering&Research Lab
Dnipropetrovsk, Ukraine

Expansion Joint in Building


Hi,

Just wondering the requirements for expansion joints in building--in Saudi, they require a building (50m x 100m for instance) to provide expansion joints for every 50m in both horizontal dimensions. Please advice if it is needed to separate the building into two parts including the structure below the ground--grade/tie beams. I understand, that it is needed for thermal expansion. What does other do?

TIA,

Mondo

RE: Flush Moment end plate connections

Bill,

I am in harmony with your rhetoric! But, Conrad's point is valid as well
...

I use purchased software not for things I don't know or understand, but I
use them to speed the process of do what it is I do know. A good software
will be transparent. I typically use Descon and they show step by step each
calculation so every aspect can be scrutinized.

The flush plate analysis is a tedious time consuming process that is ripe
for a spreadsheet. I don't need to learn how to calculate them I just need
to do it faster and since I have need of one once every year or two, it is
a toss up as to whether the time to write my own spread sheet (40hrs as
Gerald said) or calc it by hand (say 2-4hrs)

In particular the flush variety typically used in metal building systems is
what I am looking for. Alex's corner is a great resource but his is the
extended top and bottom symmetrical type.

Thanks everyone for the input,

Rand


"Bill Allen"
<t.w.allen@cox.ne
t> To
<seaint@seaint.org>
11/16/2008 12:41 cc
PM
Subject
RE: Flush Moment end plate
Please respond to connections
<seaint@seaint.or
g>




Rand -

Just curious, but if you bought a program, how would you know if it's
accurate, without errors and contains the same engineering assumptions you
would make? I guess you could compare the results of the output with a
design you did in-house, but what if the answers are different? How would
you determine if the differences are in engineering philosophy,
interpretation of the code, a different level of conservatism than yours or
just a flat out numerical error?

I'm just askin'.

T. William (Bill) Allen, S.E.
ALLEN DESIGNS
Consulting Structural Engineers
V (949) 248-8588 . F(949) 209-2509

-----Original Message-----
From: Rand W Holtham [mailto:RHoltham@CBI.com]
Sent: Friday, November 14, 2008 11:59 AM
To: seaint@seaint.org
Subject: Flush Moment end plate connections


I was setting down to write a spreadsheet to do flush and extended multiple
row moment end plate connections per AISC Design Guide #16. Is anyone aware
of a commercially available spreadsheet that is available.

TIA,

Rand


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RE: Flush Moment end plate connections

Return Receipt

Your RE: Flush Moment end plate connections
document:

was RHoltham@CBI.com
received
by:

at: 11/19/2008 12:36:00 PM

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RE: Limit on Pour Height

Jim,

 

I believe the columns of that building down on Pike or Pine Street used 10,000 psi concrete pumped from the bottom (sorry I don't know the specific building).

 

We just did a deep concrete reservoir with external vibrators and it worked well after de-bugging.  If I had it to do over again, I would have specified that the contractor do a test pour with external vibrators to prove his means and methods before production.

 

Bob Garner, S.E.

 


From: Jim Lutz [mailto:Jim.Lutz@bhcconsultants.com]
Sent: Wednesday, November 19, 2008 8:29 AM
To: seaint@seaint.org
Subject: Limit on Pour Height

 

In my experience, the biggest concern with tall pours is not form blowout or deflection, which you can design for, but how to get good consolidation. I mostly run into this in the context of tanks, where walls are poured tall with no horizontal joints. If the walls aren’t very wide, there are issues with dangling a vibrator down a deep form and trying to see, much less control what you are doing. For externally prestressed circular concrete tanks, which have fairly thin walls and not a lot of conventional reinforcement to get in the way, it is typical to cut pour windows in the forms at vertical intervals of about five feet so the form can be easily accessed with vibrators. The windows are then closed up as the pour advances. Some pretty tall walls have been built this way.

I have also heard of the concrete being pumped into the form from the bottom, but have never done it myself. It’s also important to be able to access the bottom of the form where consolidation is especially critical, near the waterstop. For tall walls on rectangular tanks this doesn’t work, because there is generally so much steel in the way you can’t get past the curtain to do anything. In situations like this, it’s a good idea to consider wall thickness to make sure you have some space between the curtains. It’s usually cheaper to go with a little wider wall to reduce steel percentage anyway, at least for conventionally reinforced rectangular tanks.

Jim Lutz, PE, SE

Senior Structural Engineer

1601 5th Avenue, Suite 500

Seattle, WA  98101

Ph: 206-505-3400

Fax: 206-505-3406

www.bhcconsultants.com      

 

 

 

RE: Limit on pour height?

Thanks all for the comments.

 

 

T. William (Bill) Allen, S.E.

ALLEN DESIGNS

Consulting Structural Engineers
 
V (949) 248-8588 F(949) 209-2509

 

Re: Snow Drift From Higher Structure

I have never come across such a provision in ASCE either. Even if there is literature to back-up using a reduced snow load, you may be in violation of ASCE if you use it without it being recognized in some manner within ASCE (or without ASCE at least giving an open-ended statement on being able to use engineering judgement for cases of large vertical offsets). I would be afraid a building inspector could shut the building down without having some sort of backing per ASCE. 
 
WH 

On Wed, Nov 19, 2008 at 12:05 PM, Jeremy White <admin@structuralae.com> wrote:
ASCE 7 restricts the affects of drift from adjacent structures to within 20 feet of higher structures.  This seems to be only a horizontal limitation and they place no restriction on vertical distance.  There must be a point where drift from a higher structure will diffuse in the same wind event that causes the drift before it reaches a low roof.  But I am not familiar with any literature that addresses this topic.  Does anyone know of any reports or data to confirm or deny my theory?  I am working on a building that is lower than an adjacent building by approximately 10 stories so I think it might be a judgement call if there is no definitive resources available.

Thanks,
Jeremy

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RE: Snow Drift From Higher Structure

The Canadian National Building Code has, in its commentary, the equations
for drift. It has a statement that over 20m (65ft) snow on the lower plane
can be considered to the standard open flat roof load. In between,
interpolate between your full calculated drift load to no drift. The reason
is that, yes the snow diffuses as it drops so that by the time it reaches
the lower level it has diluted out to the open flat roof densities.

Thor A. Tandy P.Eng, C.Eng, Struct.Eng, MIStructE
Victoria, BC
Canada

-----Original Message-----
From: Jeremy White [mailto:admin@structuralae.com]
Sent: Wednesday, November 19, 2008 9:06 AM
To: seaint@seaint.org
Subject: Snow Drift From Higher Structure

ASCE 7 restricts the affects of drift from adjacent structures to within 20
feet of higher structures. This seems to be only a horizontal limitation
and they place no restriction on vertical distance. There must be a point
where drift from a higher structure will diffuse in the same wind event that
causes the drift before it reaches a low roof. But I am not familiar with
any literature that addresses this topic. Does anyone know of any reports
or data to confirm or deny my theory? I am working on a building that is
lower than an adjacent building by approximately 10 stories so I think it
might be a judgement call if there is no definitive resources available.

Thanks,
Jeremy

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