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FW: Hankinson with different LDF's

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My apologies if you get this twice. I didn’t see it on the digest today, so I am reposting it.

 

Buddy

 

 

Joe,

 

Your reference to Appendix B is correct. If you are looking at combined loads from soil and lateral, 1.6 is the correct load duration factor. Note also that you would need to check the soil load alone with a 0.9 factor and use whichever controls.

 

Mark,

 

I know this will sound confusing, but we do not treat dowel bearing perpendicular to grain the same way we treat compression perpendicular to grain when it comes to load duration factors. Since calculating dowel connection capacity involves several different variables and several yield equations, we tried to simplify the design process by accounting for issues like this in the yield equations. Then, you can apply one load duration factor to your final Z value. I can try to answer additional questions about it, or if you want to research it further, see NDS® Appendix I and the NDS Commentary.

 

HTH

 

Buddy

 

John "Buddy" Showalter, P.E.
Vice President, Technology Transfer

 

American Wood Council

803 Sycolin Road, Suite 201

Leesburg, VA 20175

bshowalter(--nospam--at)awc.org

202-463-2769
www.awc.org

newAWClogofinaltextrightcaps-small

 

The American Wood Council (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 traditional and engineered wood products.

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

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

 

From: Mark Johnson <markajohn(--nospam--at)yahoo.com>

Subject: RE: Hankinson with different LDF's

To: seaint(--nospam--at)seaint.org

 

One more thought, according to my outdated (2001) copy of the NDS, the =0Aa=

djustment factors for compression strength perpendicular to the grain =0Ado=

 not include the LDF.=C2=A0 The LDF is only used to adjust the strength for="">

=0A compression parallel to the grain.

 

MJ

 

--- On Mon, 8/30/10, Joseph R. Grill <vveng(--nospam--at)cableone.net> wrote:

 

From: Joseph R. Grill <vveng(--nospam--at)cableone.net>

Subject: RE: Hankinson with different LDF's

To: seaint(--nospam--at)seaint.org

Date: Monday, August 30, 2010, 7:20 PM

 

Appendix B of the NDS says that the stress from any combination=0Aof loads is less than or equal to the adjusted de=

sign value modified by the=0Aload duration factor for the shortest duration=

 load in that combination of=0Aloads. =0A=0A =C2=A0 =0A=0AThat would seem t=

o agree with using a 1.6 factor on the final Z=0Asub theta.

Joseph R. Grill, PE

Verde Valley Engineering, PLLC

email: VVEng(--nospam--at)cableone.net