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RE: Overturning check

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The problem is that UBC does not specifically say that when this load
combination is used the factor of safety can be 1.0. The load combination
itself implies presence of a safety factor, but I have seen reduced dead
loads used with a safety factor of 1.5 against uplift. So to many, the
presence of a factor at the load combination level may not mean it is
directly accounting for a safety factor.


-----Original Message-----
From: Ed.Haninger(--nospam--at) [mailto:Ed.Haninger(--nospam--at)]
Sent: Wednesday, February 02, 2000 9:06 AM
To: seaint(--nospam--at)
Subject: RE: Overturning check

Allowable load combinations are used to check overturning.  There is no code
requirement to use a stability ratio over 1.0 for seismic.   This is
in 1997 UBC section 1629.1  The allowable stress combinations of section
are used.  By the way, a combination 12-16-1 has been added to the UBC:
0.90 D
+ E/1.4

Ed Haninger
Fluor Daniel
Aliso Viejo, CA

"Khosrownia, Ghassem SPK" <GKhosrownia(--nospam--at)> on 02/02/2000
08:39:29 AM

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

To:   "'seaint(--nospam--at)'" <seaint(--nospam--at)>
cc:    (bcc: Ed Haninger/AV/FD/FluorCorp)

Subject:  RE: Overturning check


Where do you get the safety factor from? I don't believe the UBC actually
gives any numbers for seismic OT. I have heard that FOS of 1.0 is adequate
for resistance against EQ induced overturning forces mainly because these
forces are not steady and they are reciprocating. What do you think?