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Re: plan irregularity type 4 - 97 UBC

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I agree with every answer Ben gave except the last additional point.  My interpretation is the Omega level forces would apply to the beam, the beam connections, and the supporting columns or posts.  The exception is the Omega level forces need not be considered at the foundation-soil interface.  This is from the Blue Book commentary.  The amplified overturning forces from the dis-continuous system must be carried through all the supporting elements to the foundation.
----- Original Message -----
Sent: Wednesday, January 22, 2003 7:43 AM
Subject: RE: plan irregularity type 4 - 97 UBC

-----Original Message-----
From: Mark Baker [mailto:shake4bake(--nospam--at)]
Sent: Tuesday, January 21, 2003 4:21 PM
To: seaint(--nospam--at)
Subject: plan irregularity type 4 - 97 UBC

I don't know how many times I have dragged myself through this, decided I am correctly interpreting the application of omega, then 2 months later a plan checker argues my interpretation resulting in my going through it all again.
Out of plane offsets of wood shear walls..... upper wall supported by beam in floor, floor diaph. transfering load to offset walls below.
The easiest way to summarize my question to the list is this:
In this load path, where does omega get applied, feel free to put yes/no behind the following items:
1. Apply omega to connection transfering lateral force from wall above to beam.[Yousefi, Ben]  Definitely Not 
2. Apply omega to hold down connections of upper wall to beam and beam to columns.[Yousefi, Ben]  Absolutely Not 
3. Design beam for omega level force from hold downs (overturning) and compression (shear force).[Yousefi, Ben]  Positively Yes 
4. Diaphragm force (keep in mind that diaphragm to be designed for Fpx load plus load input from wall above (1633.2.9 item 2)[Yousefi, Ben]  No 
4a. Apply omega to Fpx?[Yousefi, Ben]  No 
4b. Apply omega to load from wall above?[Yousefi, Ben]  Question is not clear 
5. Apply omega to shear walls below diaphragm (dependant upon awnser to 4a & 4b)?[Yousefi, Ben]  No 
I would love to have a building official response but don't let that discourage everyone else from their input. Ben Yousefi, are you out there?
One question you left out is: if the beam supporting the discontinuous shear wall is designed with Omega, should the connection for the beam, the columns supporting it, etc, all be designed for Omega? The jury is still our on that. My personal opinion is probably not. But, I could be wrong.
Ben Yousefi, SE
San Jose, CA