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Re: UBC Uplift

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I have trouble with it because the .9 factor doesn't even apply to dead load
in combination with wind, only with seismic (go figure).  One typically uses
somewhat conservative numbers to calculate DL for combination with LL.  It is
NOT conservative to then apply the same DL to resist wind uplift.  The
previous .85 factor was correct, but is now missing.

 I'd use it anyway.  There is nothing in the code to prevent you from
calculating a net uplift force that is higher than required.

Monty Hart
Associated Design Consultants, Inc.
Anchorage, Alaska

sharonb(--nospam--at) wrote:

> I had trouble with that as well.  It seems misplaced in its new location
> when the resisting requirement for wind design is still within the Wind
> Design Division (1621).
>         -----Original Message-----
>         From:   Rodriguez, Marlou [SMTP:mrodriguez(--nospam--at)]
>         Sent:   Friday, October 20, 2000 10:48 AM
>         To:     'seaint(--nospam--at)'
>         Subject:        RE: UBC Uplift
>         Tom,
>         The requirment for the 0.85 has changed to 0.9 and it is stated in
> section
>         1612.3.
>         -----Original Message-----
>         From: Tom.Hunt(--nospam--at) [mailto:Tom.Hunt(--nospam--at)]
>         Sent: Friday, October 20, 2000 10:10 AM
>         To: SEAINT(--nospam--at)
>         Subject: UBC Uplift
>         In the 1994 UBC section 1631.1 there was a requirement which reads
> "For
>         materials which use working stress procedures, dead loads shall be
>         multiplied by 0.85 when used to reduce uplift".  I do not see this
>         requirement in the 1997 UBC.  Does anyone know if this requirement
> was
>         completely deleted or perhaps moved to some other mysterious
> section??
>         Thomas Hunt, S.E.
>         Duke/Fluor Daniel