Structural Engineering: 2009-06-07

Saturday, June 13, 2009

Re: Specifications - Welding in Seismic Zone

AISC 341-05 (AISC Seismic) incorporated the critical portions of D1.8 in the body. They were able to meet the deadline and had a copy of a draft of AISC 341. So from a practical point of view if you are in seismic region where AISC 341 applies you should make sure that you read AISC 341 to see what is required.

AISC 341-05 is availible as a free douwnload.

From a good practice point of view I recommend requiring compliance with AWS D1.8 although that requires access to the document in order to understand what is required. It can be risky to reference a standard when you do not have access to it because you may not know what the options are or what information you need to put on the drawings. Using this logic you should also have access to AWS D1.1.

AISC 341-10, which is currently availible in draft form, removes the provisions that are covered in AWS D1.8 and looks to D1.8 to address the welding issues.

Mark Gilligan

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Friday, June 12, 2009

Re: Specifications - Welding in Seismic Zone

Tom

Can you discuss which sections of the new AWS D1.8 would be good to copy and include in our standard drawings and specifications.

Joe Venuti
Johnson & Nielsen Associates
Palm Springs, CA

In a message dated 6/12/2009 2:28:03 P.M. Pacific Daylight Time, Tom.Hunt@fluor.com writes:

Refugio,

The first official release of AWS D1.8 was issued too late for incorporation into our current codes such as IBC, AISC, etc. So unless your local jurisdiction has invoked it or the Engineer of Record has included it in the project requirements there is no regulation that says you have to use AWS D1.8. That said, I would suggest cutting and pasting a lot of the good words from AWS D1.8 onto your standard drawings and/or specifications. This now gets even worse as the 2009 IBC will still references the 2005 AISC Seismic Provisions so AWS D1.8 will not be officially be referenced until the 2010 AISC Seismic Provisions. IBC is still on a 3 year cycle whereas AISC has moved to a 5 year cycle.

Thomas Hunt, S.E.
Fluor

Refugio Rochin <refugio.rock.hill@gmail.com>
06/12/2009 01:50 PM
Please respond to seaint

To
seaint@seaint.org

cc

Subject
Specifications - Welding in Seismic Zone

If a project is in high seismic zone, by that nature is welding in that zone required to meet AWS D1.8? I think a better question is, when is AWS D1.8 required? Unfortunately I do not have the AWS D1.8 nor D1.1 to reference D1.8 use. ******* ****** ******* ******** ******* ******* ******* *** * Read list FAQ at: http://www.seaint.org/list_FAQ.asp * * This email was sent to you via Structural Engineers * Association of Southern California (SEAOSC) server. To * subscribe (no fee) or UnSubscribe, please go to: * * http://www.seaint.org/sealist1.asp * * Questions to seaint-ad@seaint.org. Remember, any email you * send to the list is public domain and may be re-posted * without your permission. Make sure you visit our web * site at: http://www.seaint.org ******* ****** ****** ****** ******* ****** ****** ********
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Re: Specifications - Welding in Seismic Zone

Hmm. Thank you.. Stemming from this, it is not necessary to include
AWS D1.8 if we are designing where seismic loads do not govern...?

On Fri, Jun 12, 2009 at 2:26 PM, <Tom.Hunt@fluor.com> wrote:
>
> Refugio,
>
> The first official release of AWS D1.8 was issued too late for incorporation
> into our current codes such as IBC, AISC, etc. So unless your local
> jurisdiction has invoked it or the Engineer of Record has included it in the
> project requirements there is no regulation that says you have to use AWS
> D1.8. That said, I would suggest cutting and pasting a lot of the good
> words from AWS D1.8 onto your standard drawings and/or specifications. This
> now gets even worse as the 2009 IBC will still references the 2005 AISC
> Seismic Provisions so AWS D1.8 will not be officially be referenced until
> the 2010 AISC Seismic Provisions. IBC is still on a 3 year cycle whereas
> AISC has moved to a 5 year cycle.
>
> Thomas Hunt, S.E.
> Fluor
>
>
>
> Refugio Rochin <refugio.rock.hill@gmail.com>
> 06/12/2009 01:50 PM
> Please respond to seaint
> To
> seaint@seaint.org
> cc
> Subject
> Specifications - Welding in Seismic Zone
>
>
>
>
>
> If a project is in high seismic zone, by that nature is welding in
> that zone required to meet AWS D1.8?
> I think a better question is, when is AWS D1.8 required?
> Unfortunately I do not have the AWS D1.8 nor D1.1 to reference D1.8 use.
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at: http://www.seaint.org/list_FAQ.asp
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> * This email was sent to you via Structural Engineers
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> * Questions to seaint-ad@seaint.org. Remember, any email you
> * send to the list is public domain and may be re-posted
> * without your permission. Make sure you visit our web
> * site at: http://www.seaint.org
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>
> ------------------------------------------------------------
> The information transmitted is intended only for the person
> or entity to which it is addressed and may contain
> proprietary, business-confidential and/or privileged material.
> If you are not the intended recipient of this message you are
> hereby notified that any use, review, retransmission, dissemination,
> distribution, reproduction or any action taken in reliance upon
> this message is prohibited. If you received this in error, please
> contact the sender and delete the material from any computer.
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>

Re: Specifications - Welding in Seismic Zone

Refugio,

The first official release of AWS D1.8 was issued too late for incorporation into our current codes such as IBC, AISC, etc. So unless your local jurisdiction has invoked it or the Engineer of Record has included it in the project requirements there is no regulation that says you have to use AWS D1.8. That said, I would suggest cutting and pasting a lot of the good words from AWS D1.8 onto your standard drawings and/or specifications. This now gets even worse as the 2009 IBC will still references the 2005 AISC Seismic Provisions so AWS D1.8 will not be officially be referenced until the 2010 AISC Seismic Provisions. IBC is still on a 3 year cycle whereas AISC has moved to a 5 year cycle.

Thomas Hunt, S.E.
Fluor

Refugio Rochin <refugio.rock.hill@gmail.com>
06/12/2009 01:50 PM
Please respond to seaint

To	seaint@seaint.org
cc
Subject	Specifications - Welding in Seismic Zone

If a project is in high seismic zone, by that nature is welding in that zone required to meet AWS D1.8? I think a better question is, when is AWS D1.8 required? Unfortunately I do not have the AWS D1.8 nor D1.1 to reference D1.8 use. ******* ****** ******* ******** ******* ******* ******* *** * Read list FAQ at: http://www.seaint.org/list_FAQ.asp * * This email was sent to you via Structural Engineers * Association of Southern California (SEAOSC) server. To * subscribe (no fee) or UnSubscribe, please go to: * * http://www.seaint.org/sealist1.asp * * Questions to seaint-ad@seaint.org. Remember, any email you * send to the list is public domain and may be re-posted * without your permission. Make sure you visit our web * site at: http://www.seaint.org ******* ****** ****** ****** ******* ****** ****** ********

------------------------------------------------------------ The information transmitted is intended only for the person  or entity to which it is addressed and may contain  proprietary, business-confidential and/or privileged material.   If you are not the intended recipient of this message you are  hereby notified that any use, review, retransmission, dissemination,  distribution, reproduction or any action taken in reliance upon  this message is prohibited. If you received this in error, please  contact the sender and delete the material from any computer.    Any views expressed in this message are those of the individual  sender and may not necessarily reflect the views of the company.   ------------------------------------------------------------

Specifications - Welding in Seismic Zone

Re: Tie Downs

I have *not* performed 300, or even one, such test, but as a practicing S.E. specializing in residential seismic upgrades in the Bay Area I have to ask: How much practical difference does 3/8" or even 1/2" deflection make when the objective is collapse prevention?

I realize that expectations may differ for the performance of new, and probably expensive, construction.

Ralph Hueston Kratz, S.E.

Richmond CA USA

www.rhkse.com

Sent from my iPhone 3G

On Jun 12, 2009, at 7:20 AM, "Al Commins" <al@comminsmfg.com> wrote:

In response to your posting on the SEA site.

In performing well over 300 full size shear wall tests I have developed some strong opinions.

Tie-downs connected head to tail will introduce excessive deflection. (See attached flyer example #1).

Deflection through three hd's will be well over 3/8" and may be 1/2" or more-without considering shrinkage/settling.

I suggest a threaded rod connect the shear wall directly to the foundation with the rod passing through the cripple wall.

If shrinkage/settling is a consideration (over 1/8") a screw type shrinkage compensator should be used.

IBC (Section 2305.2) and the CBC (Section 2305.2) place deflection limitations on the design of wood Diaphragms. As outlined in the SEAOC Seismology AC155 commentary, hold down deflection can contribute 83% of the allowable drift from the hold-down deformation alone. This is with a single hold-down. Three HD's will triple the movement

Comments on my analysis and the video clip (linked in the Shrinkage-Backlash flyer) are welcome.

Best Regards.

Al Commins

360 378-9484

<Al Commins.vcf>

<Shrinkage Compensators-Shrinkage-Backlash 1.pdf>

<080517 - SEAOC Seismology AC155 Final (2).pdf>

Residential project - New Orleans

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To review the project’s design and also provide periodic inspection services during construction.

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312.573.1726 facsimile

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RE: OSHPD Requirements for Surgical Lights

Paul,

Essential facilities in California require special considerations.

Larry Hauer S.E.

> Date: Fri, 12 Jun 2009 08:05:05 -0400
> Subject: RE: OSHPD Requirements for Surgical Lights
> From: ad026@hwcn.org
> To: seaint@seaint.org
>
> Not having done any OR lighting support, I have to ask the question ...
> Why are these so special?
>
> Regards
> Paul
>
> > From: "Donny Harris" <dharris@kpff-la.com>
>
> > Keith is correct, the service design criteria is very important in these
> > cases and often controls the design if you are doing odd connections
> > trying to avoid the typical clutter in an OR ceiling. Lots of bracing is
> > key (pay attention to torsion with the brace layout) and any type of
> > cantilever design should be avoided if possible. If you are installing
>
> > ...
>
> > Donny Harris, SE=20
> > California
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> * This email was sent to you via Structural Engineers
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RE: OSHPD Requirements for Surgical Lights

Not having done any OR lighting support, I have to ask the question ...
Why are these so special?

Regards
Paul

> From: "Donny Harris" <dharris@kpff-la.com>

> Keith is correct, the service design criteria is very important in these
> cases and often controls the design if you are doing odd connections
> trying to avoid the typical clutter in an OR ceiling. Lots of bracing is
> key (pay attention to torsion with the brace layout) and any type of
> cantilever design should be avoided if possible. If you are installing

> ...

> Donny Harris, SE=20
> California

Thursday, June 11, 2009

ASCE Presidential Election

ASCE Members:

Voting in the 2010 ASCE Presidential Election commences on Monday, June 15. I am writing to urge you to vote for Kathy Caldwell. I have had the pleasure of serving with Kathy on the ASCE Executive Committee, Board of Direction, and Strategic Planning Committee. Based on this experience, I know that she will be a terrific ASCE President. Four traits stand out:

(1) Values – She consistently does the right thing, even if it occasionally goes against the grain.

(2) Leadership – She listens, thinks, and then speaks … in that order.

(3) Passion – If anyone has ever had more ASCE blood in their veins, I have yet to meet them.

(4) Fun – She makes even the most tedious ASCE service enjoyable for everyone around her.

I therefore believe that Kathy Caldwell will be an excellent steward of ASCE over the next three years. I have formally endorsed her candidacy. So has ASCE's Structural Engineering Institute (SEI) and Engineering Mechanics Institute (EMI). Kathy is the only candidate who is a structural engineer, and she has no misrepresentations whatsoever in the materials posted on her campaign website.

You can visit her campaign website at:

http://kathyjcaldwell.com/

You can listen to her audio interview podcast at:

http://content.asce.org/files/other/ASCEElection_CALDWELL_V2a.mp3

And most importantly, you can vote for her at:

http://content.asce.org/Board%20Elections/2010/index.html

DISCLAIMER: While Kathy and I share the same excellent surname, we are related only by friendship and have never worked for the same employer.

Regards,

Stan R. Caldwell, P.E., SECB, F.ASCE

ASCE Executive Committee, 11/07-11/08

ASCE Board of Direction, 10/05-11/08

Chair, ASCE Technical Region, 10/05-11/08

RE: OSHPD Requirements for Surgical Lights

Larry-

Keith is correct, the service design criteria is very important in these
cases and often controls the design if you are doing odd connections
trying to avoid the typical clutter in an OR ceiling. Lots of bracing is
key (pay attention to torsion with the brace layout) and any type of
cantilever design should be avoided if possible. If you are installing
into the underside of concrete or filled deck then another area to look
at first is post installed anchors per appendix D, you may end up with a
pretty healthy bolt pattern at each support depending on your brace
geometry and equipment requirements. If you can go straight to
structural steel you are lucky. Furthermore, if you have a flexible
diaphragm and or wood structure you will likely be earning your fee!

In response to your original question in case someone has not answered
it already; I believe ASCE 7-05 section 13.3.1 does specify a vertical
component of +/- 0.2 SDS*Wp. Sorry if this has been answered already, I
am in digest mode and miss posts often.

Also, if you are doing much OSHPD equipment anchorage make sure you are
familiar with Special Seismic Certification (SSC) for equipment under
CAN 2-1708A.5. You can see all CANs on the OSHPD website.

Good luck,

Donny Harris, SE
California

Re: "Standard of Practice" for wood-frame earthquake retrofit tie-downs

Well, with that sort of personal invitation.....

This raises the whole question of what to do where the new meets the old, both in calculating loads/forces and in evaluating those forces, AND in accommodating those forces with new or existing construction.

I mean, what do we REALLY know about how the EQ forces will gather and route thru the structure above and down into the lower structure that we're reinforcing. It's not like in a new structure where we pretty much ignore the "nonstructural" interior walls and consider just the "pure" structural elements that we're designing. So, IMHO, we really don't know how the forces are coming down to the lower shear walls that we're building. If we only know force distribution to ONE significant figure, why figure overturning/uplift/etc. to 3 or more? GIGO. Call it rationalization but I don't see the sense of worrying too much about a little (theoretical calculated) uplift.

To the subject at hand: If a wall is too short in height to allow installation of a hold-down, and assuming that it has a reasonable length (say several times its height MINIMUM) I find it hard to worry too much about uplift, no matter what the numbers say.

OTOH I do consider it essential to have a reasonable number of hold-downs sprinkled throughout the structure, for general attachment of wood to concrete. (I'm thinking here primarily of improvements to the earthquake strength of the crawl space and basement and perhaps garage level of a single-family house, my usual project.) Which is why I include hold-downs at the ends, and at major openings, of ALL shear walls where it's possible to include them, regardless of the numbers (the exact opposite of the "perforated shear wall" philosophy.) The code has traditionally given short thrift to vertical forces, and yet homes have bounced off their foundations all over the place (e.g., Coalinga, etc.).

Another aspect of this is, What about the existing foundation, and its strength/continuity/etc.? What good is a new hold-down installed in a very old, deteriorated trapezoidal foundation?? Lacking rebar the foundation probably has little to offer other than the weight of a few feet of its length. Makes the effort of installing a new HD pretty much wasted.

All of this is addressed to VOLUNTARY seismic upgrades where we're trying to improve the strength/safety of the most vulnerable parts of an older home at a reasonable cost. If you're adding a story to an existing home the code requires upgrading the existing lower parts to current standards. In that instance you do whatever you have to do to make it work, including whatever foundation improvements are necessary to accomplish that. And providing whatever hold-downs are called for by the calcs.

Good question, Thor.

Ralph Hueston Kratz
Structural Engineer
www.rhkse.com

In a message dated 6/11/09 7:42:46 AM, thorm@sti.net writes:

This is a question for SF Bay Area engineers who do residential or light commercial earthquake retrofits for wood-framed buildings.

For cripple walls that are not very tall (say 18 inches or less), tie-down installation becomes a problem. Most engineers will have some degree of confidence that the self-weight of the building will resist overturning up to a certain level, without doing extensive calculations to determine tributary loads.

What calculated "raw" uplift (overturning moment/shear wall length, ignoring self-weight) do you categorically ignore? 500 pounds? 750 pounds? 1000 pounds? Or do you consider each case individually, and use your experience and judgment to decide whether you need a tie-down to resist 751 pounds?

Feel free to e-mail me off-list. If I get enough off-list responses to average, I will post the result with any highlights. I'm counting on you, Ralph.... ;-)

Thanks,

Thor Matteson
www.shearwalls.com

**************
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"Standard of Practice" for wood-frame earthquake retrofit tie-downs

This is a question for SF Bay Area engineers who do residential or light commercial earthquake retrofits for wood-framed buildings.

For cripple walls that are not very tall (say 18 inches or less), tie-down installation becomes a problem. Most engineers will have some degree of confidence that the self-weight of the building will resist overturning up to a certain level, without doing extensive calculations to determine tributary loads.

What calculated "raw" uplift (overturning moment/shear wall length, ignoring self-weight) do you categorically ignore? 500 pounds? 750 pounds? 1000 pounds? Or do you consider each case individually, and use your experience and judgment to decide whether you need a tie-down to resist 751 pounds?

Feel free to e-mail me off-list. If I get enough off-list responses to average, I will post the result with any highlights. I'm counting on you, Ralph.... ;-)

Thanks,

Thor Matteson

www.shearwalls.com

ASCE Presidential Election

Please vote for the next ASCE president on June 15. I am personally supporting Moustafa Gouda, P.E., D.GE, F.ASCE based on his Experience, Vision and Commitment.

Past ASCE president Patricia Galloway also supports Moustafa, she wrote:

Based on Moustafa’s dedication to the American Society of Civil Engineers (ASCE) combined with his experience as Treasurer and Director of the Society, I recommend Moustafa Gouda for ASCE President. I have worked with Moustafa for many years and know that he is committed to ASCE and civil engineering. Moustafa is a “rare” engineer in that he is a “local” engineer with an “global” perspective. Given the importance today for engineers to understand the global engineering challenges we face, as well as the need to integrate engineering with public policy and social management systems, there is no better candidate than Moustafa Gouda. In addition, based on his long history with ASCE, his commitment to younger engineers, his appreciation for a diverse membership, including women engineers, and his continual quest to improve the image of engineers around the world, I personally believe he is the best choice for President. I would urge you to vote and to cast your vote for Moustafa Gouda.

Dr. Patricia D. Galloway, P.E., PMP

Chief Executive Officer

Pegasus-Global Holdings, Inc.

1750 Emerick Road

Cle Elum, WA 98922

ASCE Fellow and Past President

For complete list of endorsements please visit www.moustafagouda.com

D. Matthew Stuart, P.E. S.E., F.ASCE, SECB

Senior Project Manager

Structural Department

Associate

Engineers and Consultants - CMX

200 Route 9

Manalapan, NJ 07726

732-577-9000 (Ext. 308)

908-309-8657 (Cell)

732-298-9441 (Fax)

mstuart@CMXEngineering.com

RE: Structural stuff on TV

Your script really is humorous, too bad the humor would probably only be
appreciated by a small minority of the viewers - i.e. engineers.
Otherwise I would say you would have a hit.

Thanks for sharing with the List.

D. Matthew Stuart, P.E., S.E., F.ASCE, SECB
Senior Project Manager
Structural Department
Associate
Engineers and Consultants - CMX
200 Route 9
Manalapan, NJ 07726
732-577-9000 (Ext. 308)
908-309-8657 (Cell)
732-298-9441 (Fax)
mstuart@CMXEngineering.com

-----Original Message-----
From: Michel Blangy [mailto:mblangy@satco-inc.com]
Sent: Monday, June 08, 2009 2:35 PM
To: seaint@seaint.org
Subject: RE: Structural stuff on TV

Title: Design for Passion

Cast of Characters:
Bianca, SE (Angelina Jolie)
Stiker,SE (Brad Pitt)
Ivana, Architect Certified Extreme Eco-Green Environmentally Responsible
(Daryl Hannah)
Mr. Maitland the Greedy Developer (Donald Trump)
Gerardo the Plans Examiner (Geraldo Rivera)
Mr. Grant the Chief Plans Examiner (Tony Hawk)

Time: Present

Place: Melrose Place

Setting: It's a time of prosperity. The people have developed an
insatiable
need for engineered design to satisfy their ever growing boredom with
performance enhancing drug tainted sporting events and action movies
lacking
in special effects enhancements. They crave more. More plans - extremely
detailed plans. Plans designed for extreme loads and conditions
certified by
extremely sexy engineers with extreme passions for their work ... and
other
things.

ACT I - The Office
Our stars Angelina and Brad are in their downtown Chicago office

Bianca
Dambit Striker it's not extreme enough. One more submission like this
and
I'm going to have to let you go. Mr. Maitland asked for extreme and
we're
going to give it to him! After all, he did pay us $5 million for the
most
extreme design.

Stiker
Bianca I don't understand. I engineered these beams for maximum
extremeness.
Just look at the enormity of the cement and the shear. Anyway, you can't
let
me go and you no it.

(The two fall to the floor in each other's arms - Cut to Mr. Maitland's
Office)

Secretary 1
Mr. Maitland here's your coffee

Mr. Maitland
(Sips his coffee and promptly spits it out) Your fired.

(turns to the intercom) Somebody bring me the Grandiose Spa plans STAT!
And
tell that planning commission I'm going to give them that $50 million.

(Cut to the DOBS)

Gerardo
If you think I'm going to certify this you're crazy. I have seen alot of
extreme designs and this, well, let's you better hope Mr. Grant doesn't
see
it.

Bianca
Do you know what Mr. Maitland paid for this engineered design. He can
buy
and sell your ass. Besides (Bianca grabs Gerardo's tie) when have you
ever
been able to say no to me before?

Gerardo
I'm sure we can work out the rest of these details during the
construction
phase.

..to be continued

-----Original Message-----
From: Scott Maxwell [mailto:smaxwell@umich.edu]
Sent: Monday, June 08, 2009 9:33 AM
To: seaint@seaint.org
Subject: Structural stuff on TV

For those interested, there was some structural engineering content in
the
latest episode of "In Plain Sight" on the USA Network. The episode had
a
brief portion where the one character talked about statics and
statically
determinate trusses...too bad the character sketched out statically
indeterminate truss to illustrate his point...and claimed that all
trusses
are statically determinate. I do not recall if they called the guy a
structural engineer or bridge engineer or what.

Regards,

Scott
Adrian, MI

Base Plate Design

Return Receipt

Your Base Plate Design
document:

was RHoltham@CBI.com
received
by:

at: 06/11/2009 08:34:51 AM

Wednesday, June 10, 2009

RE: OSHPD Requirements for Surgical Lights

Larry,

This is not an answer to your question but rather a potential over-riding
design limit.

I ran into some surgical lights a little while back for a proposed renovation
project. The permissible service load rotation specified by the manufacturer
for the lights was less than I could achieve without significant renovation
of the lightly framed bar-joist roof. If your supporting structure is stiff,
this will not be a problem, but it's something to consider if your framing is
other that beefy. In my case, it killed the project and started the surgeons
thinking about relocation to another part of the facility.

It would surprise me if standard anchorage for the equipment was not grossly
conservative versus 0.33 Fp.

-----Original Message-----
From: lrhauer@earthlink.net [mailto:lrhauer@earthlink.net]
Sent: 09 June 2009 23:00
To: SEAOC
Subject: OSHPD Requirements for Surgical Lights

To All,

I am designing the supports for surgical lighting in an existing California
hospital, ("SPC-1" rated). I could design it to the 1995 UBC but would need
to amplify the forces by a factor of "4" for flexible equipment, so I've
decided to design it to the '07 CBC, using Chapter 13 of the ASCE 7-05. There
use to be a requirement for OSHPD work that a vertical component of 0.33Fp be
included, (i.e. footnote "20" of the '01 CBC Table 16A-O), but I can't seem
to find it anywhere in the '07 CBC or ASCE. Does anyone know if this
requirement of 1/3*Fp as a vertical load is still required by OSHPD and where
do I find it in the code?

Thanks in advance,

Larry Hauer, S.E.

NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer.

Tuesday, June 9, 2009

RE: FRP Retrofit

Tim,

Things to consider when using FRP retrofit:

1) The assembly needs to be fire proofed which will add additional weight.
2) When used in areas with considerable temperature variations debonding will occur between the base concrete and the FRP.

Regards!

Francis Hsi, PE
Highway Structures Maintenance Engineer

From: thilton@lhcengineers.com
To: seaint@seaint.org
Subject: FRP Retrofit
Date: Tue, 9 Jun 2009 10:34:18 -0400

Can somebody point me to a good source of info for using FRP "strips" to reinforce existing concrete?

Specifically I'm interested in strengthening an existing flat plate slab to add a new penthouse on top. The addition will also require a large number of 12" to 14" square penetrations for new mechanical units. I need some ballpark figures for a cost estimate ASAP.

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

Windows Live™ SkyDrive™: Get 25 GB of free online storage. Get it on your BlackBerry or iPhone.

Re: EMT Properties

Actually, this is used all the time in ceilings

-gm

On Tue, Jun 9, 2009 at 5:59 PM, Bill Polhemus <bill@polhemus.cc> wrote:

Sounds like a contractor has ton of the stuff and wants to use it in lieu of stuff he'd have to buy.

When all you have is a hammer...

William L. Polhemus, Jr. P.E.
Via iPhone 3G

On Jun 9, 2009, at 6:26 AM, Jim Getaz <jgetaz@shockeyprecast.com> wrote:

        Ray,

                Even if I knew the properties of the tubes, from what I've seen of the connectors for EMT, I'm not sure I'd want to be involved in using it structurally.

        Jim Getaz

RE: Structural stuff on TV

I am pretty sure they did not do THAT one. <grin>

Regards,

Scott

Adrian, MI

From: Bill Polhemus [mailto:bill@polhemus.cc]
Sent: Tuesday, June 09, 2009 12:28 PM
To: <seaint@seaint.org>
Subject: Re: Structural stuff on TV

I do not recall if they called the guy a

structural engineer or bridge engineer or what.

Oh, surely they called him "the Architect," right?

Re: EMT Properties

Sounds like a contractor has ton of the stuff and wants to use it in lieu of stuff he'd have to buy.

When all you have is a hammer...

William L. Polhemus, Jr. P.E.

Via iPhone 3G

On Jun 9, 2009, at 6:26 AM, Jim Getaz <jgetaz@shockeyprecast.com> wrote:

        Ray,

                Even if I knew the properties of the tubes, from what I've seen of the connectors for EMT, I'm not sure I'd want to be involved in using it structurally.

        Jim Getaz

RE: FRP Retrofit

Tim:

You may find some useful information in ICC ES evaluation reports at http://www.icc-es.org/reports/index.cfm?csi_num=03930&view_details=yes

From: Timothy Hilton [mailto:thilton@lhcengineers.com]
Sent: Tuesday, June 09, 2009 7:34 AM
To: seaint@seaint.org
Subject: FRP Retrofit

Can somebody point me to a good source of info for using FRP “strips” to reinforce existing concrete?

Specifically I’m interested in strengthening an existing flat plate slab to add a new penthouse on top. The addition will also require a large number of 12” to 14” square penetrations for new mechanical units. I need some ballpark figures for a cost estimate ASAP.

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

OSHPD Requirements for Surgical Lights

To All,

I am designing the supports for surgical lighting in an existing California hospital, ("SPC-1" rated). I could design it to the 1995 UBC but would need to amplify the forces by a factor of "4" for flexible equipment, so I've decided to design it to the '07 CBC, using Chapter 13 of the ASCE 7-05. There use to be a requirement for OSHPD work that a vertical component of 0.33Fp be included, (i.e. footnote "20" of the '01 CBC Table 16A-O), but I can't seem to find it anywhere in the '07 CBC or ASCE. Does anyone know if this requirement of 1/3*Fp as a vertical load is still required by OSHPD and where do I find it in the code?

Thanks in advance,

Larry Hauer, S.E.

RE: FRP Retrofit

Quake Wrap as previously mentioned is a good product with good support. Another consideration would be Helitech http://hj3.com/. They also have good technical support.

Regards, Harold Sprague

From: thilton@lhcengineers.com
To: seaint@seaint.org
Subject: FRP Retrofit
Date: Tue, 9 Jun 2009 10:34:18 -0400

Can somebody point me to a good source of info for using FRP "strips" to reinforce existing concrete?

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

Windows Live™ SkyDrive™: Get 25 GB of free online storage. Get it on your BlackBerry or iPhone.

Re: EMT Properties

Thanks Robert.

I have the dimensions and section properties. I will only be using it for axial tension members only. So, all I need is a conservative estimate of allowable tension stress.

Regards,

Ray Shreenan

----- Original Message -----

From: Garner, Robert

To: seaint@seaint.org

Sent: Tuesday, June 09, 2009 7:06 AM

Subject: RE: EMT Properties

Try Allied Tube. Also, you can get dimensions of EMT from the McMaster Carr website or the Grainger Catalog website, and calculate your own section properties.

I frequently design miscellaneous struts from EMT as you are doing. I conservatively use 20 ksi allowable bending stress, but usually column buckling controls and the actual stress is much less.

I like the stuff because it is very ductile - it has to be so Sparky can bend all those offsets and such.

Bob Garner, S.E.

From: rshreenan1@verizon.net [mailto:rshreenan1@verizon.net]
Sent: Monday, June 08, 2009 4:00 PM
To: seaint@seaint.org
Subject: EMT Properties

Does anyone know where I can find the structural properties for EMT tubing?

It is proposed for use as duct support and bracing.

Thanks,

Ray Shreenan

Re: FRP Retrofit

You may want to contact Santa Monica, CA City Engineer Tony Antich at tony.antich@smgov.net or 310 458-8721.

They have use FRP for several years on concrete columns of several parking structures.

Stan Scholl, P.E.

Civil Engineer

Re: EMT Properties

Jim:

They use it as a tension member only by flattening the ends and drilling hole for a 3/8" diameter MB. All I need is the ultimate tension stress or a conservative value for axial tension.

Regards,

Ray Shreenan

----- Original Message -----

From: Jim Getaz

To: seaint@seaint.org

Sent: Tuesday, June 09, 2009 4:26 AM

Subject: Re: EMT Properties

        Ray,

                Even if I knew the properties of the tubes, from what I've seen of the connectors for EMT, I'm not sure I'd want to be involved in using it structurally.

        Jim Getaz

Re: Structural stuff on TV

I do not recall if they called the guy a

structural engineer or bridge engineer or what.

Oh, surely they called him "the Architect," right?

RE: FRP Retrofit

Great comment Bill!

Larry Hauer, SD.E.

From: bill@polhemus.cc
To: seaint@seaint.org
Subject: Re: FRP Retrofit
Date: Tue, 9 Jun 2009 11:20:20 -0500

ACI 440.2

Or I could do it all for you. Hire me!

Meaning no disrespect, but all these academic-types and their start-up ventures to "consult" on xFRP strengthening...that ship has sailed.

Unless you have some highly unusual application, you don't need a Ph.D. to design this stuff.

William L. Polhemus, Jr. P.E.

Via iPhone 3G

On Jun 9, 2009, at 9:34 AM, "Timothy Hilton" <thilton@lhcengineers.com> wrote:

Can somebody point me to a good source of info for using FRP "strips" to reinforce existing concrete?

Specifically I'm interested in strengthening an existing flat plate slab to add a new penthouse on top. The addition will also require a large number of 12" to 14" square penetrations for new mechanical units. I need some ballpark figures for a cost estimate ASAP.

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

Windows Live™ SkyDrive™: Get 25 GB of free online storage. Get it on your BlackBerry or iPhone.

Re: FRP Retrofit

ACI 440.2

Or I could do it all for you. Hire me!

Meaning no disrespect, but all these academic-types and their start-up ventures to "consult" on xFRP strengthening...that ship has sailed.

Unless you have some highly unusual application, you don't need a Ph.D. to design this stuff.

William L. Polhemus, Jr. P.E.

Via iPhone 3G

On Jun 9, 2009, at 9:34 AM, "Timothy Hilton" <thilton@lhcengineers.com> wrote:

Can somebody point me to a good source of info for using FRP "strips" to reinforce existing concrete?

Specifically I'm interested in strengthening an existing flat plate slab to add a new penthouse on top. The addition will also require a large number of 12" to 14" square penetrations for new mechanical units. I need some ballpark figures for a cost estimate ASAP.

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

RE: FRP Retrofit

Tim,

One of my college professors, Mo Ehasni, has started a company that specialzes in this type of retrofit. Check out their web site at www.quakewrap.com.

--Kipp Martin

Portland, Oregon

From: Timothy Hilton [thilton@lhcengineers.com]
Sent: Tuesday, June 09, 2009 7:34 AM
To: seaint@seaint.org
Subject: FRP Retrofit

Can somebody point me to a good source of info for using FRP "strips" to reinforce existing concrete?

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com

FRP Retrofit

Can somebody point me to a good source of info for using FRP “strips” to reinforce existing concrete?

I would appreciate any insight.

Thanks,

Timothy K. Hilton, E.I.

Engineering Intern

LHC STRUCTURAL ENGINEERS

P.O. Box 10567

1015 Wade Avenue

Raleigh, NC 27605-0567

919.832.5587 x 20

thilton@lhcengineers.com