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RE: Definition of A sub B in Rho evaluation

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Larger Ab reduces the ratio of total shear (story level 1) to the unit
shear of the wall being considered.   For a single shearwall, increasing Ab
reduces the value of rho.  Rho is intentionally (and unjustly) punitive to
light-frame construction and as the demand forces are artificially
increased by a big rho, you may have the opportunity to increase Ab (by
interpretation), which may counter a reduction in the value of rho, which
will reduce demand forces, that may require less hardware to facilitate
capacities, that may be interpreted as less conservative, because you have
realized a minor reduction of  the monstrous fairy tale of rho...  eg.  A
fair price may be seventy-five cents.   They charged you a dollar.  For
twenty-cents more, you may realize a five-cent return.  It (rho) is a
bureaucratic masterpiece.

Just because I'm fatigued and frustrated with the experience of calculating
and 'accounting' for the identification of the "least redundant" element in
light-frame (cut-up, custom, "architecturally free", non-box like, bizaro,
ect.) projects that I might apply the most punitive value of rho to all
elements resisting force in the direction of consideration (yes, I have
more on that hot-button), I have surrendered to the designation of rho=1.5
for all cases involving light frame models mentioned above.

Shamelessly, as a form of civil disobedience, tea-in-the-bay, and all that,
I  typically disregard building overhang area unless the mass of the
projection is significant and true savings may be realized in construction.





sharonb(--nospam--at)slarchitects.com on 07/20/2000 07:26:51 AM

Please respond to seaint(--nospam--at)seaint.org

To:   seaint(--nospam--at)seaint.org
cc:
Subject:  RE: Definition of A sub B in Rho evaluation


Thank you.
I'm just trying to get a grip on this...Can you explain why a larger Ab is
not more conservative?

> -----Original Message-----
> From:   Tom VanDorpe [SMTP:tvandorpe(--nospam--at)vcaengineers.net]
> Sent:   Monday, July 17, 2000 6:59 PM
> To:     seaint(--nospam--at)seaint.org
> Subject:     RE: Definition of A sub B in Rho evaluation
>
>
> The Code defines "Floor Area" in section 207.
>
> The definition reads: "Floor Area is the area included that the
> surrounding
> exterior walls of a building or portion thereof, exclusive of eave shafts
> and courts.  The floor area of a building, or portion thereof, not
> provided
> with surrounding exterior walls shall be the usable area under the
> horizontal projection of the roof or floor above.".
>
> Therefore, use the exterior walls wherever possible.  Also, inflating Ab
> isn't a conservative move, so be cautious about which number you use.
>
> Sincerely,
>
> Tom VanDorpe, P.E.
> VanDorpe Chou Associates, Inc.
> Orange, California
> (714) 978-9780
>
>
> original message:
> -------------------------------------------------------------------------
> From: sharonb(--nospam--at)slarchitects.com
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Definition of A sub B in Rho evaluation
>
> Thanks Paul
> It is refreshing to know that nobility is not dead!
> I also want to add that there are design examples in the Seismic Design
> Manuals (for 1997 UBC) published by SEAOC.  They include rho
calculations.
> Sharon
>
> > -----Original Message-----
> > From: Paul_Reilly(--nospam--at)dot.ca.gov [SMTP:Paul_Reilly(--nospam--at)dot.ca.gov]
> > Sent: Thursday, July 13, 2000 8:01 AM
> > To:   seaint(--nospam--at)seaint.org
> > Subject:   RE: Definition of A sub B in Rho evaluation
> >
> >
> > Ouch B & C.  Unnecessary roughness?  My interpretation for the code
> > required standard of practice is 1936.  I would use 1600, just because.
> >
> >
> >
> >
> >
> > Charles Greenlaw <cgreenlaw(--nospam--at)speedlink.com> on 07/12/2000 05:49:08 PM
> >
> > Please respond to seaint(--nospam--at)seaint.org
> >
> > To:   seaint(--nospam--at)seaint.org
> > cc:
> > Subject:  RE: Definition of A sub B in Rho evaluation
> >
> >
> > Isn't that the waiting line for people who want to get onto select
> > committees and write riddles and snipe hunts into building code?
> >
> > Charles O. Greenlaw SE   Sacramento CA
> >
> > At 08:13 AM 07/12/2000 -0700, you wrote:
> > >The correct answer is 1936.  Consider the drip line.
> > >
>
>
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