Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: WOOD SHEARWALLS

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Sounds basically correct, but there is a wrinkle for Seismic Zones 3 & 4
from Section 1806.6.1, which requires 2x2x3/16" plate washers on all bolts
at the foundation level.  This seems to eliminate the possibility of not
using plate washers in Seismic Zones 3 & 4 (which is what the footnote
applies to also).  We've had the same on-going discussion in our office, and
arrived at similar conclusions to yours.

Does anyone know the origin of these requirements?  It sure would help us
apply these provisions to meet the intent of the code if we understood what
was wanted.

Conrad Guymon, P.E.

----- Original Message -----
From: "Gerard Madden" <gmadden(--nospam--at)duquette-eng.com>
To: <SEAINT(--nospam--at)SEAINT.ORG>
Sent: Friday, November 09, 2001 2:54 PM
Subject: WOOD SHEARWALLS


> Here is my attempt to decipher the shearwall stud and sill plate sizes per
> Table 23-ii-i-1 footnote 3 (Revised) in the 1997 UBC (Page 2-288).:
>
> Okay ... Deep breath...
>
> CASE 1: Allowable Shear of Wall is 350 plf and below
>
> 2x vertical studs are okay
> 2x sill plates are okay
> 2x mudsills are okay without plate washers
>
> CASE 2: Allowable Shear of Wall is at least 350.1 plf AND Actual Shear in
> Wall is 600 plf or less
>
> 2x vertical studs are okay if they receive field nailing
> 3x vertical studs are required when two sheathing edges are edge nailed
into
> the same stud
> 2x Sill plates are okay if only 1 sheathing edge is edge nailed into the
> sill plate
> 3x Sill plates are required if two sheathing edges are edge nailed into
the
> same sill plate
> 3x Mudsills are required if I do not use plate washers or I use greater
than
> 50% of the anchor bolt capacity.
> OPTION: I can use 2x Mudsills if I provide plate washers and limit the
> demand to the anchor bolts to 50% of capacity
>
> CASE 3: Allowable Shear of Wall is at least 350.1 plf AND Actual Shear in
> Wall is at least 600.1 plf
>
> Same as CASE 2 except 3x mudsills are always required.
>
>
> If I am incorrect on these interpretation, could you please point out my
> misunderstandings.
>
> Now my Questions...
>
> 1) Are the plate washers required on the mudsill for case 3? Are engineers
> always specifying the plate washers for good practice?
>
> 2) I am assuming "Foundation Sill" means floor plates and mudsill plates.
Is
> that correct? Otherwise, how could a mudsill have "abutting panel" nailing
> into it.
>
>
> Thanks in Advance,
> -Gerard
> SJ, CA
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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
> *   without your permission. Make sure you visit our web
> *   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 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********