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Re: Wood floor beam shear connection

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Title: Re: Wood floor beam shear connection

2001/2005 NDS(r) 11.3.2.4 states:

"When dowel-type fasteners with D >= 1/4" are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers, Feperp shall be used in determination of the dowel bearing strength of the main member, Fem."

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.

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From: Scott Maxwell <smaxwell(--nospam--at)engin.umich.edu>
To: seaint(--nospam--at)seaint.org
Subject: Re: Wood floor beam shear connection
Jim,
From chapter 5 of the 3rd edition of the Wood Engineering and Construction Handbook by Faherty:
"Lateral Resistance in End Grain. The design value in lateral resistance for a nail or spike into the end grain (parallel to wood fibers) is only two-thirds (Ceg=0.67) of the design value given for lateral load when the nail or spike is driven into the side grain."

This let me to look up the Ceg factor in the NDS (I used the 2001 NDS). It is located in section 11.5.2.2, which states:

"When dowel-type fasteners are inserted in the end grain of the main member, with the fastener axis parallel to the wood fibers, the nominal lateral design values, Z, shall be multipled by the end grain factor, Ceg=0.67."

Now, it does not really address which bearing strength to use (i.e. perpendicular or parallel to the grain). I would take the worst case and use that and then use the 2/3 factor on top of that.

Maybe Buddy @ AFPA can offer more insight.
HTH,
Scott
Adrian, MI

On Fri, 30 Dec 2005, Jim Wilson wrote:
> Which, if any, NDS values can be used for dowel design where the
> dowels are driven through a primary support member and sticking out
> and into the end grain of a junior member? The end reaction of the
> junior member is shear only - about 1300 lbs (Cd=100). In this case,
> I'm reviewing a 3" glulam butt into the side of a 5" and the owner
> wants a blind connection. The beam is already erected.
>
> The contractor is proposing 10" long 5/8" lags, which would be
> countersunk through the primary member and have about 6" of
> penetration into the junior member. I've browsed Breyer and looked
> through the NDS books and can't find any example of this condition.
> If using the tabulated lag bolt values, is it Z perp or Z parallel, or
> neither.
>
> The condition is somewhat similar to determining a wall stud's
> lateral resistance where it is nailed top and bottom through the plate
> and into the end grain of the stud.
>
> Thanks in advance.
>
> Jim Wilson
> Stroudsburg, PA