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RE: UBC Section 1612.2.1, Exception 2

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I have a course book that must be a later addition.  It seems there was an
error in the 1997 UBC chapter 19 Div VIII section 1928 stuff.  My course
book reads:       

"......

Problem...Load factors of 1928.1.2 based on 1988 edition of ASCE 7 and do
not reflect earthquake load  (E) at ultimate load level as adopted in
1612.2.

Solution...Use of load combinations in 1612.2.1 [Eqs (12-1) thru (12-6)
without the (1.1) multiplier] and set of strength reduction factors listed
in 1928.1.1 are compatible, without further modification."

I see designers use the UBC 1612 load combinations with the 1.1 factor for
seismic design all the time.  The 1.1 factor is included in ACI 318-99
section 9.2.3 but then is not included in IBC 1605.2.1 which is referenced
in IBC concrete amendments.


Scott M Haan  P.E.
Plan Review Engineer
Building Safety Division http://www.muni.org/building, 
Development Services Department,
Municipality of Anchorage
phone: 907-343-8183   fax: 907-249-7399
mailto:haansm(--nospam--at)ci.anchorage.ak.us

> -----Original Message-----
> From:	Bill Allen, S.E. [SMTP:Bill(--nospam--at)jrma.com]
> Sent:	Wednesday, March 28, 2001 10:36 AM
> To:	seaint(--nospam--at)seaint.org
> Subject:	UBC Section 1612.2.1, Exception 2
> 
> I have some hand written notes in my seminar book when I attended the ICBO
> Seminar on the 1997 UBC Earthquake Regulations. I believe the presenter
> was
> S.K. Ghosh and I believe he said that this exception, which requires
> multiplying the load factors by 1.1, should be deleted and is not
> appropriate.
> 
> My questions:
> 
> 1. Does anyone else have similar notes?
> 
> 2. Has anything been published publicly (such as a SEAOC position paper)
> which states this?
> 
> 3. (a big one), what about masonry?
> 
> TIA,
> 
> Bill Allen, S.E.
> 
>