Need a book? Engineering books recommendations...

# RE: Shear Wall Deflection IBC vs. UBC

• To: seaint(--nospam--at)seaint.org
• Subject: RE: Shear Wall Deflection IBC vs. UBC
• From: "Jake Watson" <jwatson(--nospam--at)utahisp.com>
• Date: Thu, 15 Aug 2002 08:56:27 -0600

```I think the UBC formula is correct.  In order to determine LATERAL
deflection, you must consider deflection of the hold-downs.  The UBC formula
takes the hold-down deflection, divides it by the length of the wall
(converting to a rotation angle) then multiplies the rotation angle by the
wall height.  This is similar to the simulated pushover analysis that is
done for concrete shearwalls.  This seams "logical".

That said, you will find the IBC equation in the LRFD for Wood (ASCE 16-95)
book.  Given the rest of the equation is derived base on mechanics of
materials, I think the IBC/LRFD equation is wrong.

Jake Watson, P.E.
Salt Lake City, UT

P.S. If you can get your hands on the original derivation of the equation,
it will make more sense.  You can find a reference to this in the SEAINT
archives.  I believe it was about two years ago.

-----Original Message-----
From: Jim Kestner [mailto:jkestner(--nospam--at)somervilleinc.com]
Sent: Wednesday, August 14, 2002 7:50 PM
To: 'SEAINT'
Subject: Shear Wall Deflection IBC vs. UBC

Has anyone noticed that the last term of the formula for the deflection of
wood shear walls in IBC is not the same as the one in the UBC? The formula
in SI units appears to be quite different also. Which one is correct?

Jim K.

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted