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RE: re/ Fp Values

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Well, he (the plan checker) had a difficult time being specific (this is why
I got by - he said "this time"), but I believe he wanted me to consider a
M/d component in the horizontal direction (he said "like a steel moment
frame"). I could only guess that I would have to take the M produced by the
shear in the pier multiplied by the pier height then divide that by "d"
determined by the distance between the top plate and the horizontal strap at
the header then add this force to the drag force. I am only speculating here
since the plan checker could not give me a specific reference or example
(FWIW, I do not have Breyer's 4th edition, merely his 3rd and I learned
timber design based on his 2nd).

Of course, I think I would prefer (in the future) to design these conditions
in accordance with a "perforated wall" (a la APA report 157) instead of a
"wall frame". The sheathing gets bumped up a little but no straps and the
analysis method is simpler.

Hopefully, the forthcoming design manual will demonstrate AND ALLOW FOR
EITHER METHOD (anyone listening out there?).

I wonder how that 1997 UBC FAQ is coming?


Bill Allen, S.E.
Laguna Niguel, CA

|| -----Original Message-----
|| From: Cain, William [mailto:bcain(--nospam--at)]
|| Sent: Thursday, September 16, 1999 11:42 AM
|| To: 'seaint(--nospam--at)'
|| Subject: RE: re/ Fp Values
|| Bill-
|| Just curious.  How did he want you to do the "opening"
|| analysis?  Or did he
|| know what he wanted?
|| Bill Cain, SE
|| Oakland, CA
|| 	-----Original Message-----
|| 	From:	Bill Allen [SMTP:Bill(--nospam--at)]
|| 	Sent:	Thursday, September 16, 1999 10:52 AM
|| 	To:	seaint(--nospam--at)
|| 	Subject:	RE: re/ Fp Values
|| 	<snip>
|| 	Getting a little ahead of myself, I recently got into
|| an argument
|| with a
|| 	plan checker with regards to the design and detailing
|| of openings in
|| shear
|| 	walls (see Fig 23-II-1). After twenty something years
|| of structural
|| 	engineering, I thought I knew how to do this. Not
|| according to the
|| plan
|| 	checker. For the horizontal check/connection, I
|| calculated the drag
|| force
|| 	based on the shear above the opening and the shear below the
|| opening. I
|| 	provided blocking and strapping to accommodate this
|| drag force. For
|| the
|| 	vertical component (continuous framing member-king stud), I
|| calculated the
|| 	axial force by multiplying the shear force in the pier
|| by the pier
|| height
|| 	and dividing by the pier width. This is like: T=C=M/d. I divided
|| this force
|| 	by the distance from the top of the pier to the top
|| plate to give a
|| distance
|| 	in which this "chord force" could be transferred into the panel
|| above the
|| 	pier. I then provided boundary nailing that would transfer this
|| force. As
|| 	shocking as this may seem, the plan checker did not
|| think that this
|| was an
|| 	adequate "Design for force transfer ... based on a rational
|| analysis" (see
|| 	2315.1, 5th paragraph). Sheesh. At this point in my career, I no
|| longer am
|| 	interested in getting into a debate with the plan
|| checker. I just
|| want to
|| 	finish the job and move on to the next one. It would
|| have been nice
|| to have
|| 	an example (such as one that may be included in an
|| upcoming design
|| 	manual???) to reference.
|| 	<snip>
|| 	Bill Allen, S.E.
|| 	Laguna Niguel, CA