Structural Engineering: 2008-02-03

Saturday, February 9, 2008

Re: Bending Stress for Southern Pine #2, NDS Example 5

> Prolly No. 3, more commonly used.

Hi Bill,

For Southern Pine 2"-4" thick No. 3, Fb = 850 psi.

I think he made a mistake.

Sam

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Re: Bending Stress for Southern Pine #2, NDS Example 5

Szuchuan Chang wrote:
> Hi Lists,
>
> At Northern California, I don't use Southern Pine too often.
>
> In the "NDS Examples" Example #5 on page 33, the Fb:=1050 psi was used.
>
> However, when I check the NDS Supplement page 38, the Fb is listed for
> No. 2 is 1500 psi.
>
> Did he misplace the Ft for Fb?
>
Prolly No. 3, more commonly used.

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Bending Stress for Southern Pine #2, NDS Example 5

Hi Lists,

At Northern California, I don't use Southern Pine too often.

In the "NDS Examples" Example #5 on page 33, the Fb:=1050 psi was used.

However, when I check the NDS Supplement page 38, the Fb is listed for
No. 2 is 1500 psi.

Did he misplace the Ft for Fb?

Southern Pine should have better strength than Douglas Fir. Isn't it?

Please help.

Thanks

Sam Chang,
Cupertino CA

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CBO

I know, CBO stands for Certified Building Official. What kind of exam do they have to take and pass? What is the organization that keeps record of these people? (Just like the State Board does engineering licenses).

Thanks

Antonio S. Luisoni

Who's never won? Biggest Grammy Award surprises of all time on AOL Music.

SEAW Wind Procedure

As a lot of you are doing, I am trying to study the new wind provisions. I have a copy of the "SEAW's handbook of a Rapid-Solutions Methodology for Wind Design" and I am trying to see if it will be beneficial to me.

Most of the work I do is for small fairly simple structures. I am hoping there is someone out there (in the Washington area) that can explain something to me.

I am looking at the Application Problem 2 in Appendix B1. I am looking at the uplift loading at the roof, which is a low slope roof. When they are finding the uplift coefficient from Figures 3-4EB and 3-4ED they are taking into account a tributary area, "TA". In the example that I am looking at they have determined that TA = (9/2)(50)=225 square feet. I can't find (in any of the three books in the set) a definition of "TA". I don't see where this particular "TA" comes from. This tributary area doesn't seem to correlate to that which is calculated at the roof in example 4.

Is there anyone out there that is familiar with the SEAW methodology that can explain?

Thanks,

Joe Grill

Friday, February 8, 2008

RE: Yet another Wind question

Hey guys, go have a beer already.

-----Original Message-----You might need to apply C&C pressures to a MWFRS element...as another load
case to consider (i.e. a shearwall will get designed in place due to MWFRS
pressures, but out of plane for C&C pressures). But, I get your
point/intent. You are 100% correct in that it is function not size that
matters (OK, my dirty mind is now having fun with that one).

Regards,

Scott
Adrian, MI

-----Original Message-----
From: Christopher Banbury [mailto:cbanbury(--nospam--at)arkengineering.net]
Sent: Friday, February 08, 2008 11:26 AM
To: seaint(--nospam--at)seaint.org
Subject: RE: Yet another Wind question

I wasn't really meaning to comment on the application of MWFRS pressures to
C&C elements.

I sometimes hear the argument that C&C pressures must be applied to all
MWFRS elements with a TA less than 700sf. I was just pointing out that the
definition of MWFRS elements is based on function and not related to TA.

Christopher Banbury, PE
President

Ark Engineering, Inc.
PO Box 10129, Brooksville, FL 34603
22 North Broad ST, Brooksville, FL 34601
Phone: (352) 754-2424
Fax: (352) 754-2412
www.arkengineering.net

-----Original Message-----
From: Scott Maxwell [mailto:smaxwell(--nospam--at)umich.edu]
Sent: Thursday, February 07, 2008 2:31 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: Yet another Wind question

"The tributary area of 700sf is not a part of the definition of MWFRS but is
a helpful exception that allows C&C elements with TA larger than 700sf to be
treated as MWFRS. As you say, if the intent is there then the rules should
be revised."

That is what we (or at least I) was talking about. The point is the MWFRS
tables can end up getting used for MORE than just MWFRS pressures. For C&C
items with large trib areas, you end up using the MWFRS pressures for C&C
purposes.

You are correct in that such an element would NOT be a MWFRS ELEMENT...it
would still be a C&C ELEMENT. That distinction is determined by its
function as you pointed out. But, the point was that some C&C ELEMENTS get
large enough that you use MWFRS PRESSURES to design it.

It is an important distiction even if it ultimately just semantics (you only
really care if it is a MWFRS or C&C element to determine which method is
used to determine pressures...thus, it matters little where you CALL an
element a MWFRS or C&C element if it ultimately using the MWFRS method to
get the wind design pressures).

Regards,

Scott
Adrian, MI

http://www.seaint.org/sealist1.asp
*
* Questions to seaint-ad(--nospam--at)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: Yet another Wind question

You might need to apply C&C pressures to a MWFRS element...as another load
case to consider (i.e. a shearwall will get designed in place due to MWFRS
pressures, but out of plane for C&C pressures). But, I get your
point/intent. You are 100% correct in that it is function not size that
matters (OK, my dirty mind is now having fun with that one).

Regards,

Scott
Adrian, MI

-----Original Message-----
From: Christopher Banbury [mailto:cbanbury@arkengineering.net]
Sent: Friday, February 08, 2008 11:26 AM
To: seaint@seaint.org
Subject: RE: Yet another Wind question

I wasn't really meaning to comment on the application of MWFRS pressures to
C&C elements.

Christopher Banbury, PE
President

Ark Engineering, Inc.
PO Box 10129, Brooksville, FL 34603
22 North Broad ST, Brooksville, FL 34601
Phone: (352) 754-2424
Fax: (352) 754-2412
www.arkengineering.net

-----Original Message-----
From: Scott Maxwell [mailto:smaxwell@umich.edu]
Sent: Thursday, February 07, 2008 2:31 PM
To: seaint@seaint.org
Subject: RE: Yet another Wind question

Regards,

Scott
Adrian, MI

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RE: Fire wall/shear wall on property line

Helium ballons...solves all those gravity problems. Of course, the building might move up and down in unsettling ways!

Regards,

Scott

Adrian, MI

-----Original Message-----
From: Benjamin Maxwell [mailto:enginerd666@yahoo.com]
Sent: Friday, February 08, 2008 12:40 PM
To: seaint@seaint.org
Subject: Re: Fire wall/shear wall on property line

Yeah, those darn col-yuums are always in everyone's way. When are we engineers going to learn to train gravity?

Only 24 feet columns? Come on, have you ever seen the columns on the 101 California Street building in San Francisco? It's enough to give you the jitters. Look at the photo on the right. I used to work a block away and it scared me to eat lunch in this building's shadow.

http://en.wikipedia.org/wiki/101_California_Street

Jeff, do us all a favor and let us know how this situation works out. Thanks!

-Ben

Jeff Hedman <jeff_h@lrpope.com> wrote:

Ben,

This is also an option, but the way this particular building is, the beams and columns supporting the building would be 24 feet high. Also, the bottom 12’ of wall is a 12” thick concrete retaining wall and the top of the wall is an 8” masonry wall, there is a 4 “ gap between the beams and columns. The columns would also be sticking out into the space which the client didn’t want. So we began investigating the double wall option mentioned earlier.

Jeff

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Benjamin H. Maxwell, S.E.

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RE: ASCE 3 follow up

Gary,

I heard back from Steve Roehrig, SDI's Managing Director. He confirmed what you indicated. The C, NC, and RD documents have gone the approval process with ANSI, so they should carry the weight and "officiality" required to be adopted into the ICC family.

SDI's Design Manual No. 31 contains all three documents.

-Ben

"Ehrlich, Gary" <gehrlich@nahb.com> wrote:

Ben,

Per Section 2209.1, the deck itself should comply with the AISI North American Specification for the Design of Cold-Formed Structural Steel Members (2001 edition w/2004 supplement referenced in the IBC). I see the NASPEC is referenced in the ER. So the actual deck itself is covered by the IBC; it would appear to be just the design procedure for the composite slab and composite deck that's referencing an outdated spec. And even there, I'd say you're covered by the general language in Section 1604.4 for engineering analysis; anything that would qualify as a "rational analysis" (which I presume CCD-2 would) should thus be acceptable.

(I'll grant that I haven't designed in high-wind or high-seismic areas; I'm used to the NE where code officials don't seem to look at much else than the design criteria in the general notes and the statement of special inspections. YMMV in CA or other high-hazard areas.)

Interestingly, the SDI has a proposal in for the looming ICC hearings that adds their standards for composite, non-composite and roof deck (C1.0-06, NC1.0-06, and RD1.0-06) and expands 2209.2 to cover all steel decks. So the 2009 IBC ought to have the problem fixed.

Regards,

Gary

Gary J. Ehrlich, PE
Program Manager, Structural Codes & Standards
National Association of Home Builders (NAHB)
1201 15th Street, NW, Washington, DC 20005
ph: 202-266-8545 or 800-368-5242 x8545
fax: 202-266-8369
gehrlich@nahb.com

From: Benjamin Maxwell [mailto:enginerd666@yahoo.com]
Sent: Wednesday, February 06, 2008 7:55 PM
To: seaint@seaint.org
Subject: ASCE 3

List Engineers,

2006 IBC, 2007 CBC, etc. refer to ASCE 3 for cold-formed metal deck - see IBC 2209.2 (CBC is the same).

So, first, this ASCE 3 document was published in '93 or so and has not been updated since. It's also hard to find, and I literally did a nice jig when I found it in one of our outdated and neglected library zones amidst spider webs and dust.

Once I had this document in hand, I went to Verco to look for the references to ASCE 3. I couldn't find any in my Verco catalog and technical manual. Then I went to the Verco ICC report. Here I found only a reference to ICC AC 43 for steel floor and roof decks.

In the AC 43 document ICC allows design in accordance with EITHER ASCE 3 OR the Steel Deck Institute's Composite Deck Design Handbook (CCD2 - 1997). See Sections 3.4.1 and 3.4.2.

From what I have gathered referring to the Steel Deck Institute web site and other information we have in our office, the CCD2 reflects more current physical testing that included the positive contributory effects of composite steel framing as opposed to the older study documented in ASCE 3 that considered non-composite steel framing.

Back to my point. My question is that this seems open up a loop hole in the code that could allow steel deck construction that meets ICC standards, but does not technically meet IBC standards, correct? In other words to gain ICC approval my deck can meet CCD2 but ignore ASCE 3 requirements. This seems to be outside the intent of the current IBC requirements.

I have an e-mail in to the Steel Deck Institute that I sent Monday, but I can't wait any longer. I need answers!!!!

Any help or insight would be appreciated.

Thanks,

Ben Maxwell

Benjamin H. Maxwell, S.E.

Never miss a thing. Make Yahoo your homepage.

Benjamin H. Maxwell, S.E.

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Re: Simpson Titen HD not approved for use in concrete

simpson is really pushing the use of their Strong-Bolt wedge anchor. It meets the criteria for use in cracked concrete per ACI 318, appendix D. hth.

2008/2/8 Jeff Hedman <jeff_h@lrpope.com>:

Simpson's catalog shows all kinds of applications for using the Titen HD bolt in concrete. However, if you read the ICC ES report, only masonry loads are shown in the report. I can't find anything that says the Titen HD can be used in cracked concrete. If that is true, can this product not be used for any shear wall sill plates or hold downs?

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--
David Topete, SE

Simpson Titen HD not approved for use in concrete

Simpson's catalog shows all kinds of applications for using the Titen HD bolt in concrete. However, if you read the ICC ES report, only masonry loads are shown in the report. I can't find anything that says the Titen HD can be used in cracked concrete. If that is true, can this product not be used for any shear wall sill plates or hold downs?

Re: Good Reference for Light Gage Metal Framing?

AISI publications, such as the specification and commentary, framing standards,
and design guides, are available at a discount for Cold-Formed Steel Engineers
Institute (CFSEI) members at their website at www.cfsei.org . The CFSEI also
provides technical notes and design guides that help designers understand the
AISI specification and standards provisions as well as providing typical
cold-formed steel AutoCAD details for download.

________________________________________
From: mail [mail@strand-engineering.com]
Sent: Thu 2/7/2008 1:59 PM
To: seaint@seaint.org
Subject: Good Reference for Light Gage Metal Framing?
What is the best resource for learning more about light gage metal framing? The
AISI standards look good, but I wonder if they have any practical examples. Are
the AISI standards enough or would I need a textbook to understand how to use
the standards? If so, what is a good reference to have?

Taylor W. Motley, PE
Strand Engineering, LLC

******* ****** ****** ****** ******* ****** ****** ********

Re: Fire wall/shear wall on property line

Yeah, those darn col-yuums are always in everyone's way. When are we engineers going to learn to train gravity?

Only 24 feet columns? Come on, have you ever seen the columns on the 101 California Street building in San Francisco? It's enough to give you the jitters. Look at the photo on the right. I used to work a block away and it scared me to eat lunch in this building's shadow.

http://en.wikipedia.org/wiki/101_California_Street

Jeff, do us all a favor and let us know how this situation works out. Thanks!

-Ben

Jeff Hedman <jeff_h@lrpope.com> wrote:

Ben,

This is also an option, but the way this particular building is, the beams and columns supporting the building would be 24 feet high. Also, the bottom 12' of wall is a 12" thick concrete retaining wall and the top of the wall is an 8" masonry wall, there is a 4 " gap between the beams and columns. The columns would also be sticking out into the space which the client didn't want. So we began investigating the double wall option mentioned earlier.

Jeff

No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.516 / Virus Database: 269.19.21/1265 - Release Date: 2/7/2008 11:17 AM

Benjamin H. Maxwell, S.E.

Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.

Re: Shop Drawings

For me the hardest part of the shop drawing experience was trying to get the owner or architect (design prime) to write their project specifications in a manner that worked for the team. It was never pleasant.

In my experience the CDs would go out to bid and THEN after the contracts were awarded the discussion about shop drawings would begin. At that point the contractor is holding all the cards and you're going to have to perform at their mercy. So if it's not settled early on, forget about it being a smooth, electronic process that saves trees.

On bigger steel office buildings this means certain doom for younger engineers left to transfer red marks to six sets of prints. It's nothing but wasted productivity, writer's cramps, and ink-stained hands from there on out.

That's also one aspect of construction administration that can make or break a project's profitability.

Being on the owner's side now, I certainly do not miss the shop drawing review process.

-Ben Maxwell

"Jordan Truesdell, PE" <seaint2@truesdellengineering.com> wrote:

In Adobe Acrobat 7 (Pro): Document | Digital Signatures | Sign this Document, then choose the Certify option in the popup. I enter my password, why I'm signing, and indicate where in the document I'd like to visually apply the certification mark.

I self certify, and will email my public key (again, generated within Acrobat) to anyone who needs to verify the digital signature. I'm halfway to getting the public key available on my website so that I'm not involved in the verification process (nobody has ever asked, to be honest), but have been too busy to update my home page to link to the key.

If I were not so cheap, I'd pay Verisign $595 a year and they would provide me a private key, and make my public key available to whomever asked. As a bonus, the timestamp would be tied to their timeserver. Since nobody in the AEC industry really cares when a stamp is signed, I'm not too worried about my certification being based on the time of my local machine.
Jordan
Jerry Coombs wrote:
Certify the set? How are you doing that (I digress)

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Benjamin H. Maxwell, S.E.

Never miss a thing. Make Yahoo your homepage.

Re: light gage steel framing

Hey Bob, I think that's Ms. Breezy Bowes, at least the last I spoke with her...

-Ben Maxwell

Bob Freeman <robert.freeman@idsse.com> wrote:

Hi Taylor:

Try the Light Steel Framing Manual, Second Edition by MetalFraming.org.

My copy was provided by www.steelnetwork.com, Mr. Breezy Bowes.

With Joy and Hope,

Bob Freeman, AIA, EIT

IDS Group, Inc.

(949) 387-8500

Benjamin H. Maxwell, S.E.

Never miss a thing. Make Yahoo your homepage.

RE: Minimum edge distance OR back to the treated lumber question.....

Thanks Buddy,
This is in line with the past provisions as noted in the last AITC Manual
that I do have a copy of. The only comment related to nails was sufficient
distance to avoid tear or splitting (paraphrased). I think I noted this as
well since my AITC manual only lists the values that Scott provided for lag
screws and bolts in single or dual shear and where metal side plates are
used in the connection. This has not really changed for a long time. I did
download the NDS 2005 commentary from your link and thank you. I was on the
AWC site yesterday but could not find the information by searching and
sought this list only to save some time if anyone (such as you) could
provide a link.

Thank you again and best regards,
Dennis

-----Original Message-----
From: Showalter, Buddy [mailto:Buddy_Showalter@afandpa.org] On Behalf Of AWC
Info
Sent: Friday, February 08, 2008 5:31 AM
To: seaint@seaint.org
Subject: RE: Minimum edge distance OR back to the treated lumber
question.....

Scott/Dennis,

One qualifier on the use of NDS(r) 11.5 - it only applies for D>=1/4"
fasteners. For nails and wood screws, see the NDS Commentary. Table
C11.1.5.6 for recommended nail spacing. There's a similar table for wood
screws as well in C11.1.4.

If you don't have a NDS Commentary, you can download one here:
http://www.awc.org/pdf/NDSCommentary2005.pdf

HTH

Buddy

John "Buddy" Showalter, P.E.
Director, Technical Media
AF&PA/American Wood Council
1111 19th Street, NW, Suite 800
Washington, DC 20036
P: 202-463-2769
F: 202-463-2791

http://www.awc.org

The American Wood Council (AWC) is the wood products division of the
American Forest & Paper Association (AF&PA). AWC develops
internationally recognized standards for wood design and construction.
Its efforts with building codes and standards, engineering and research,
and technology transfer ensure proper application for engineered and
traditional wood products.

*********************
The guidance provided herein is not a formal interpretation of any AF&PA
standard. Interpretations of AF&PA standards are only available through
a formal process outlined in AF&PA's standards development procedures.

*********************

From: "Scott Maxwell" <smaxwell@umich.edu>
To: <seaint@seaint.org>
Subject: RE: Minimum edge distance OR back to the treated lumber
question.....

Take a look at section 11.5 of the 2005 NDS, since you now fall under =
the 2006 IBC which references the 2005 NDS. It has adjustment factors
for = Edge and End distance. In particular, Table 11.5.1A is for Edge
Distance. = For if the loading is parallel to grain, then if l/D <=3D 6
(where l is the = lesser of the length of the fastner in the main wood
member or the length of = the fastner in the secondary wood member(s)
and D is the diameter of the
fastner) then minimum edge distance is 1.5D. If l/D > 6, then it is =
1.5D or 1/2 the spacing between rows, whichever is greater. If the
loading is perpendicular to grain, then for a loaded edge it is 4D and
for an = unloaded edge it is 1.5D. =20 Regards, =20 Scott Adrian, MI

-----Original Message-----
From: Gerard Madden, SE [mailto:gmse4603@gmail.com]=20
Sent: Thursday, February 07, 2008 8:29 PM
To: seaint@seaint.org
Subject: Re: Minimum edge distance OR back to the treated lumber
question.....

Use PT Sheathing and go down to 6" (DSA used to allow this when they had
= a 12" clearance requirement (Using PT Sheathing, you could go to 6")
or = use a small strip of sidewalk against it and use Sheet metal
flashing instead = of soil. DSA now has the same 8" clearance as the
normal building code.
Edge distances for nailing is not something that is quantified that I =
know, but I like to have 3/8" min from edge of stud to C.L. of nail for
8d's
-gm

On Feb 7, 2008 4:31 PM, Dennis Wish <dennis.wish@verizon.net> wrote:

What is the allowable edge distance for a 10d or 8d Common nail in D.F.
lumber parallel to grain? Also, what is the minimum distance from the =
nail to the end or edge of a plywood panel to prevent splitting. If I
started with two panels joined on a horizontal diaphragm over a 2x joist
with = 1/8" gap per APA requirement for panel expansion, the remaining
lap is 11/16-inch. How much of this is actually needed.

Of course my question goes back to using a 3x6 Pressure Treated Mud-sill
against a foundation or slab on grade which is only 6-inches clear from
finished soil. Is there sufficient room to lap =BD" of the plywood over
= the 3x plate and boundary nail without splitting the sill plate or the
end of = the plywood panel (assume =BC-inch clearance to centerline of
nail). I am = only assuming a boundary nailing of 6-inch on center and
not closer at this = point just to see if I can resolve this conflict.

Help?

Dennis

******* ****** ****** ****** ******* ****** ****** ********

RE: Yet another Wind question

I wasn't really meaning to comment on the application of MWFRS pressures
to C&C elements.

I sometimes hear the argument that C&C pressures must be applied to all
MWFRS elements with a TA less than 700sf. I was just pointing out that
the definition of MWFRS elements is based on function and not related to
TA.

Christopher Banbury, PE
President

Ark Engineering, Inc.
PO Box 10129, Brooksville, FL 34603
22 North Broad ST, Brooksville, FL 34601
Phone: (352) 754-2424
Fax: (352) 754-2412
www.arkengineering.net

-----Original Message-----
From: Scott Maxwell [mailto:smaxwell@umich.edu]
Sent: Thursday, February 07, 2008 2:31 PM
To: seaint@seaint.org
Subject: RE: Yet another Wind question

"The tributary area of 700sf is not a part of the definition of MWFRS
but is
a helpful exception that allows C&C elements with TA larger than 700sf
to be
treated as MWFRS. As you say, if the intent is there then the rules
should
be revised."

That is what we (or at least I) was talking about. The point is the
MWFRS
tables can end up getting used for MORE than just MWFRS pressures. For
C&C
items with large trib areas, you end up using the MWFRS pressures for
C&C
purposes.

You are correct in that such an element would NOT be a MWFRS
ELEMENT...it
would still be a C&C ELEMENT. That distinction is determined by its
function as you pointed out. But, the point was that some C&C ELEMENTS
get
large enough that you use MWFRS PRESSURES to design it.

It is an important distiction even if it ultimately just semantics (you
only
really care if it is a MWFRS or C&C element to determine which method is
used to determine pressures...thus, it matters little where you CALL an
element a MWFRS or C&C element if it ultimately using the MWFRS method
to
get the wind design pressures).

Regards,

Scott
Adrian, MI

Re: Fire wall/shear wall on property line

Thanks for the input everyone, I think we will go ahead with the double wall.

Jeff

RE: Minimum edge distance OR back to the treated lumber question.....

Buddy,

Thanks for reminding me. I am just so used to using that section for pins
and bolts that we are using in timber framing that I completely forgot.
Don't tend to use those small, puny things called nails (or "girly dowels"
as the Governator might call them) in timber framing!

Regards,

Scott
Adrian, MI

-----Original Message-----
From: Showalter, Buddy [mailto:Buddy_Showalter@afandpa.org] On Behalf Of AWC
Info
Sent: Friday, February 08, 2008 8:31 AM
To: seaint@seaint.org
Subject: RE: Minimum edge distance OR back to the treated lumber
question.....

Scott/Dennis,

If you don't have a NDS Commentary, you can download one here:
http://www.awc.org/pdf/NDSCommentary2005.pdf

HTH

Buddy

John "Buddy" Showalter, P.E.
Director, Technical Media
AF&PA/American Wood Council
1111 19th Street, NW, Suite 800
Washington, DC 20036
P: 202-463-2769
F: 202-463-2791

http://www.awc.org

The American Wood Council (AWC) is the wood products division of the
American Forest & Paper Association (AF&PA). AWC develops internationally
recognized standards for wood design and construction. Its efforts with
building codes and standards, engineering and research, and technology
transfer ensure proper application for engineered and traditional wood
products.

*********************
The guidance provided herein is not a formal interpretation of any AF&PA
standard. Interpretations of AF&PA standards are only available through a
formal process outlined in AF&PA's standards development procedures.

*********************

From: "Scott Maxwell" <smaxwell@umich.edu>
To: <seaint@seaint.org>
Subject: RE: Minimum edge distance OR back to the treated lumber
question.....

Take a look at section 11.5 of the 2005 NDS, since you now fall under = the
2006 IBC which references the 2005 NDS. It has adjustment factors for = Edge
and End distance. In particular, Table 11.5.1A is for Edge Distance. = For
if the loading is parallel to grain, then if l/D <=3D 6 (where l is the =
lesser of the length of the fastner in the main wood member or the length of
= the fastner in the secondary wood member(s) and D is the diameter of the
fastner) then minimum edge distance is 1.5D. If l/D > 6, then it is = 1.5D
or 1/2 the spacing between rows, whichever is greater. If the loading is
perpendicular to grain, then for a loaded edge it is 4D and for an =
unloaded edge it is 1.5D. =20 Regards, =20 Scott Adrian, MI

Use PT Sheathing and go down to 6" (DSA used to allow this when they had = a
12" clearance requirement (Using PT Sheathing, you could go to 6") or = use
a small strip of sidewalk against it and use Sheet metal flashing instead =
of soil. DSA now has the same 8" clearance as the normal building code. Edge
distances for nailing is not something that is quantified that I = know, but
I like to have 3/8" min from edge of stud to C.L. of nail for 8d's -gm

On Feb 7, 2008 4:31 PM, Dennis Wish <dennis.wish@verizon.net> wrote:

What is the allowable edge distance for a 10d or 8d Common nail in D.F.
lumber parallel to grain? Also, what is the minimum distance from the = nail
to the end or edge of a plywood panel to prevent splitting. If I started
with two panels joined on a horizontal diaphragm over a 2x joist with = 1/8"
gap per APA requirement for panel expansion, the remaining lap is
11/16-inch. How much of this is actually needed.

Of course my question goes back to using a 3x6 Pressure Treated Mud-sill
against a foundation or slab on grade which is only 6-inches clear from
finished soil. Is there sufficient room to lap =BD" of the plywood over =
the 3x plate and boundary nail without splitting the sill plate or the end
of = the plywood panel (assume =BC-inch clearance to centerline of nail). I
am = only assuming a boundary nailing of 6-inch on center and not closer at
this = point just to see if I can resolve this conflict.

Help?

Dennis

******* ****** ****** ****** ******* ****** ****** ********

RE: basic lateral force question

This is what I have done as well. You can then use that "relative rigidity"
with a stiff diaphram analysis that distributes loads proportional to the
relative rigidities in combination with the relative torsional
rigidities/effects.

And while wind might govern overall, you will still likely want to run the
seismic numbers as minimum seiscmic loading may still lead to higher loads
to use for the moment frames due to minimum load distribution to the moment
frames required for "dual systems" in the seismic provisions. In other
words, the requirements that for a dual system of moment frames with shear
walls, the moment frames must be designed to take at least 25% of the
seismic load no matter what happens relative rigidity wise. Thus, while it
might be likely that the overall seismic loading might be less than wind, it
is possible that 25% of the seismic loading might still be more than what
get proportioned by relative rigidity from wind.

Regards,

Scott
Adrian, MI

-----Original Message-----
From: Adam Vakiener [mailto:avakiener@southernae.com]
Sent: Friday, February 08, 2008 7:19 AM
To: SEAINT
Subject: RE: basic lateral force question

Andrew,

When I have had rigid frames combined with shear walls I have calculated
the deflection of each under a hypothetical lateral load (say 1 kip or
10 kips). I then simply use the inverse of this deflection as the
rigidity of each element.

You are right that the shear walls will take most of the load. It is
hard to make a rigid frame anywhere near as rigid as a shear wall.

Adam Vakiener, P.E.
Structural Engineer
Southern A&E, LLC

> From: "Andrew Kester, P.E." <akester@cfl.rr.com>
> To: "seaint" <seaint@seaint.org>
> Subject: basic lateral force question
>
> This is a multi-part message in MIME format.
>
> ------=_NextPart_000_01DB_01C869BF.3F1D6460
> Content-Type: text/plain;
> charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable
>
> 3 story office building with some CMU reinforced shear walls along the
> = core of the building. On the second floor the floor extends out
> beyond = the CMU walls on the north and south sides to have covered
> parking. = Project in Florida, ZERO SEISMIC but 120mph wind.
>
> A rigid diaphgragm (floor) of either a hollow core slab system or deck
> = and concrete on steel joists.
>
> I can use steel moment frames at the very N and S sides of the
> building, = and then at the middle I will use some of the CMU shear
> walls and = elevator/stair cores.
>
> I have the SDI Manual and have been looking through it. Are there any
> = limits on diaphgram cantilever I should be aware of (other than =
> allowable shear force limits and deflection)? Both with steel deck,
> conc = and steel deck, or hollow core? I am thinking with hollow core
> I may = need to increase the 2" topping and provide a reinforcing mesh
> in excess = of what we normally would do for gravity and normal
> shear...
>
> Also, if I go the moment/braced frame route, how do I distribute the =
> story shear between CMU walls and the frames? With the rigid
> diaphgrams = at the floors I would normally assume this is a function
> of the rigidity = of each shear wall and frame. Or can I just use trib
> area method? I know = how to do this with all CMU walls, but how do I
> calc relative rigidities = of CMU walls and steel frames? I am
> thinking the CMU walls are going to = be MUCH stiffer than the steel
> frames, so that the steel frames would = not see much of the load... I
> am talking about doing a torsional shear = analysis to distribute the
> shear forces, but with a mixed system I am = not sure how that would
> work. CMU- been there, done that, may go that = route if possible.
>
> Kind of need a starting point here because I think I can do it a few =
> different ways.
>
> Thanks in advance,
> Andrew
>
>
> Andrew Kester, P.E.
> Principal/Project Manager
> ADK Structural Engineering, PLLC
> 1510 E. Colonial Ave., Suite 301
> Orlando, FL 32803

******* ****** ****** ****** ******* ****** ****** ********

Re: Fire wall/shear wall on property line

Ben,

This is also an option, but the way this particular building is, the beams and columns supporting the building would be 24 feet high. Also, the bottom 12' of wall is a 12" thick concrete retaining wall and the top of the wall is an 8" masonry wall, there is a 4 " gap between the beams and columns. The columns would also be sticking out into the space which the client didn't want. So we began investigating the double wall option mentioned earlier.

Jeff

RE: basic lateral force question

See below.

Regards,
Harold Sprague

From: akester@cfl.rr.com
To: seaint@seaint.org
Subject: basic lateral force question
Date: Thu, 7 Feb 2008 19:25:49 -0500

3 story office building with some CMU reinforced shear walls along the core of the building. On the second floor the floor extends out beyond the CMU walls on the north and south sides to have covered parking. Project in Florida, ZERO SEISMIC but 120mph wind.

A rigid diaphgragm (floor) of either a hollow core slab system or deck and concrete on steel joists.

I can use steel moment frames at the very N and S sides of the building, and then at the middle I will use some of the CMU shear walls and elevator/stair cores.

I have the SDI Manual and have been looking through it. Are there any limits on diaphgram cantilever I should be aware of (other than allowable shear force limits and deflection)? Both with steel deck, conc and steel deck, or hollow core?

***Not any other than what you have listed. Deflection is a bit difficult to calculate, but there are procedures.

I am thinking with hollow core I may need to increase the 2" topping and provide a reinforcing mesh in excess of what we normally would do for gravity and normal shear...

***I would agree.

Also, if I go the moment/braced frame route, how do I distribute the story shear between CMU walls and the frames? With the rigid diaphgrams at the floors I would normally assume this is a function of the rigidity of each shear wall and frame. Or can I just use trib area method? I know how to do this with all CMU walls, but how do I calc relative rigidities of CMU walls and steel frames?

***You should use relative stiffness. Jim Amrhein, "Reinforced Masonry Engineering Handbook" has some good guidance in this area. He has some coefficients of rigidity in the back that are helpful. You can find a used copy for about $25. New is about $150.

I am thinking the CMU walls are going to be MUCH stiffer than the steel frames, so that the steel frames would not see much of the load... I am talking about doing a torsional shear analysis to distribute the shear forces, but with a mixed system I am not sure how that would work. CMU- been there, done that, may go that route if possible.

Kind of need a starting point here because I think I can do it a few different ways.

Thanks in advance,

Andrew

Andrew Kester, P.E.
Principal/Project Manager
ADK Structural Engineering, PLLC
1510 E. Colonial Ave., Suite 301
Orlando, FL 32803

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Re: Shop Drawings

In Adobe Acrobat 7 (Pro): Document | Digital Signatures | Sign this Document, then choose the Certify option in the popup. I enter my password, why I'm signing, and indicate where in the document I'd like to visually apply the certification mark.

I self certify, and will email my public key (again, generated within Acrobat) to anyone who needs to verify the digital signature. I'm halfway to getting the public key available on my website so that I'm not involved in the verification process (nobody has ever asked, to be honest), but have been too busy to update my home page to link to the key.

If I were not so cheap, I'd pay Verisign $595 a year and they would provide me a private key, and make my public key available to whomever asked. As a bonus, the timestamp would be tied to their timeserver. Since nobody in the AEC industry really cares when a stamp is signed, I'm not too worried about my certification being based on the time of my local machine.

Jordan

Jerry Coombs wrote:

Certify the set? How are you doing that (I digress)

RE: Minimum edge distance OR back to the treated lumber question.....

Scott/Dennis,

If you don't have a NDS Commentary, you can download one here:
http://www.awc.org/pdf/NDSCommentary2005.pdf

HTH

Buddy

John "Buddy" Showalter, P.E.
Director, Technical Media
AF&PA/American Wood Council
1111 19th Street, NW, Suite 800
Washington, DC 20036
P: 202-463-2769
F: 202-463-2791

http://www.awc.org

*********************

From: "Scott Maxwell" <smaxwell@umich.edu>
To: <seaint@seaint.org>
Subject: RE: Minimum edge distance OR back to the treated lumber
question.....

On Feb 7, 2008 4:31 PM, Dennis Wish <dennis.wish@verizon.net> wrote:

Help?

Dennis

Re: Shop Drawings

Certify the set? How are you doing that (I digress)

>>> On 2/8/2008 at 7:23 AM, "Jordan Truesdell, PE" <seaint2@truesdellengineering.com> wrote:

I prefer PDF submissions - it's $1.25 a sheet I don't have to pay for scanning, and an hour or two of copying I don't have to pay my drafter for jr engineer. I mark text notes on the plans, stamp them digitally, and certify the set before emailing them back. Somebody else can kill trees (or, more importantly, pay some one to kill and process them).

For sketches, we hand sketch, scan, note the sheet, and bind the scanned sketches into the shop drawing set. Takes about 30 extra seconds if you include the walk to the scanner, and I get to use graph paper and a pencil instead of trying to draft in red pen on blueline paper.

Jordan

Jnapd@aol.com wrote:

David

How easy is it to draw on the pdf's and how accurate can you draw or correct a detail ?

Joe Venuti
Johnson & Nielsen Associates
Palm Springs, CA

n a message dated 2/7/2008 1:29:21 PM Pacific Standard Time, dfisher@fpse.com writes:

We've been experimenting on a couple projects with the following scenario:

GC posts the drawings on the project website in pdf format

Each entity (arch/SE/GC) makes its corrections on the same file in a different color

Once corrections are complete, "marked up" pdf files released to the sub-contractor

This saves time, money and trees.

Funny thing is, some subs actually refuse this option, instead, sending six sets of bluelines; of which

Only one or two are used. The "original" is marked up and the rest are along for the ride.

David L. Fisher SE PE

Senior Director

Who's never won? Biggest Grammy Award surprises of all time on AOL Music.

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Re: Shop Drawings

Having a small office, I have a problem with storage. The office is
full, so the old stuff goes home to the basement ( for you people in the
warm bottom half of the continent, a basement is a large concrete lined
hole in the ground under a house). I specify that shop drawings should
be in CAD preferably 11x17; for those still doing manual drawings, I
specify that they are to be scanned and submitted by e-mail or on CD. I
still get the odd illiterate who brings or sends X hard copies. I mark
up the drawings and then scan the 11x17's in house and send the large
sheets to an outside copy service for scanning-$0.35 per sq ft. There
are cheaper services in the next city but my service is about 1.5 miles
away. In turn, this saves me storing piles of drawings, courier fees,
printing out lots of copies and best of all saves a lot of time looking
for drawings that have been forgotten and buried or whatever. I just
look up the scanned drawings in the archives. Case in point: lost
customer drawings last week-took an hour to find them.
Others in my area are starting to go this way.
Gary
PS; I hate it when other consultants ask my contractor customers for 5
or 6 sets of drawings. I prepare one set which I sign and seal and
then make additional photocopies and then you have to courier those.

domdean@aol.com wrote:
> I was wondering how people are handling the latest "innovation" where
> shop drawings are now e-mailed out instead of the normal process where
> an office may get 3 or 4 (or more) hard copies. Some of the projects
> can be fairly extensive with shop drawings. My general notes include
> one indicating that I am to receive a minimum of 3 sets of shop
> drawings for whatever is applicable (reinforcing steel, structural
> steel, etc.). There can be a substantial cost (both in time required
> and paper involved). It seems as though it is one more item that's
> being forced on the engineer of record.
>
> Domenic DeAngelo P.E.
> ------------------------------------------------------------------------
> More new features than ever. Check out the new AOL Mail
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Re: Shop Drawings

Jordan

Jnapd@aol.com wrote:

David

How easy is it to draw on the pdf's and how accurate can you draw or correct a detail ?

Joe Venuti
Johnson & Nielsen Associates
Palm Springs, CA

n a message dated 2/7/2008 1:29:21 PM Pacific Standard Time, dfisher@fpse.com writes:

We've been experimenting on a couple projects with the following scenario:

GC posts the drawings on the project website in pdf format

Each entity (arch/SE/GC) makes its corrections on the same file in a different color

Once corrections are complete, "marked up" pdf files released to the sub-contractor

This saves time, money and trees.

Funny thing is, some subs actually refuse this option, instead, sending six sets of bluelines; of which

Only one or two are used. The "original" is marked up and the rest are along for the ride.

David L. Fisher SE PE

Senior Director

Who's never won? Biggest Grammy Award surprises of all time on AOL Music.