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Re: Gross overturning

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Matthew,
 
Look at load combinations, Section 1612, as referred to in 1630.8.  12-10 and 12-16.1 are for ASD.
 
V. Steve Gordin, SE
Irvine CA
 
 
----- Original Message -----
From: Matthew
Sent: Thursday, January 31, 2008 11:06
Subject: Re: Gross overturning

We asked for code sections which stated the F.O.S. and 1630.8 was the code section he gave.  Does it matter that we are using ASD level loads?  I see nothing stating that an increase in F.O.S. is required because ASD loads were used but I just want to make sure.  Thank you. 

 

 
On Jan 31, 2008 10:53 AM, Steve Gordin <sgordin(--nospam--at)sgeconsulting.com> wrote:
If not amended by the city, UBC/CBC Section 1630.8 governs.  It essentially says that the issue of seismic overturning is taken care of by checking against load combinations 12-6, 12-10 and 12-16.1. 
 
V. Steve Gordin, SE
Irvine CA
----- Original Message -----
From: Matthew
Sent: Thursday, January 31, 2008 10:30
Subject: Re: Gross overturning

It is not the policy; the plan checker is insisting that it is common practice to use a 1.5 F.O.S.  Every design professional, including himself, he was talked to uses 1.5 when using loads at ASD level.  The shear walls range from 1.15-1.2, it would be extremely costly to get a 1.5 F.O.S.  Can anyone offer advice on convincing him that he is wrong? :)



On Jan 31, 2008 10:16 AM, Steve Gordin <sgordin(--nospam--at)sgeconsulting.com> wrote:
There is none.  For seismic, everything about 1.0 is OK.  I usually use not less than 1.2.
It may be a city policy, then you are out of luck.
 
V. Steve Gordin, SE
Irvine CA
----- Original Message -----
From: Matthew
Sent: Thursday, January 31, 2008 10:08
Subject: Gross overturning

I have a plan check comment stating that a 1.5 F.O.S. is required for gross overturning on any building shear wall from seismic loads at ASD level.  The project is under the 97 UBC; I have been unable to find any code section that requires a 1.5 F.O.S, the only requirement is for earth retaining walls.  Could anyone please comment on where I can find the section?  Or how they have resolved a similar situation?
 
Thank you