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Re: Seismic Upgrade ..... Appeal to those who created the code

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In a message dated 5/21/99 11:47:45 PM Pacific Daylight Time, Sadre(--nospam--at)AOL.COM 

 It is important to consider the relative stiffness of wood shear walls and 
 other vertical elements of the lateral force resisting system.  An example 
 would be steel moment frames used in combination with wood shear walls.  If 
 the steel frames are quite flexible, the shear walls are likely to carry a 
 large portion of the story shear than would be suggested by a tributary area 
 analysis.  The relative flexibiltiy of steel moment frame may have 
 contributed to damage to tuck-under parking (soft story) buildings during 
 1994 Northridge earthquake [Mendes, 1995].

I can't disagree with this last sentence more!!  Most tuck under parking 
(soft story condition) did not have steel moment frames.  Usually 3-1/2" 
diameter pipe columns or  wood posts were used to support usually wood beams. 
 These beams & columns were adequate to support gravity loads, however 
lateral loads were designed to be resisted by rotation.  Strangely enough, 
numerous structures of this type suffered no noticeable damage, although 
quite a few structures were distressed and damaged

Andrew Vidikan  P.E.