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RE: Tilt-up In-Plane Shear

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I personally feel the plan checker is correct.  You selected an R from chapter 16 for the lateral system.  Are you using special reinforced concrete walls or ordinary plain walls, etc?  These are only defined in section 1921, which is strength design.  I don't know of any corresponding section in the ASD section.  If you have a rational method to prove the ASD section is equivalent to section 1921, you can try it.  But, it seems it would be easier to simply perform the checks outlined in section 1921.
Just my thoughts,
Jake Watson, P.E.
Salt Lake City, UT

-----Original Message-----
From: ASQENGG2(--nospam--at) [mailto:ASQENGG2(--nospam--at)]
Sent: Thursday, June 19, 2003 11:21 PM
To: seaint(--nospam--at)
Subject: Tilt-up In-Plane Shear

I designed a tilt-up shear wall (in-plane shear) using the ASD method.  The consultant plan checker said that I have to meet the requirements of 1921.6 which is a part of Division II ( Strength Design).

It is very clear that at the very start of Chapter 19, Section 1900.3 say that the design of concrete structures shall be in accordance with one of the following methods, which are the LRFD (Division II) and ASD (DivisionVI).  So if you go to Division VI, there is no section in it that referred you back to 1921.6. 

The plan checker of the City argued that 1926.1.2 said that for design of members not covered by this section, appropriate provisions of this code shall apply.  This ambiguous statement is their weapon for me to meet the 1921.6 requirements which I believe is not referring to structures designed using ASD.

My argument is that structures designed using ASD undergo elastic deformation and doesn't need further provisions in order to work.  We need to provide special provision for members designed using LRFD because such structures undergo inelastic deformation.  My analogy to this is like in steel design when using SMRF as against OMRF. SMRF will undergo inelastic yielding while the OMRF act more in elastic behavior (bounce back to its original shape). 

Thanks a lot for any of your comments.

A. S. Quilala Jr.