Need a book? Engineering books recommendations...

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

RE: 3X Plates and Washers on Intermediate Anchors

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I still think you are right about the bolt holes becoming larger.  I've
never actually observed this condition, but I've seen plenty of nails
that are loose due to wood shrinkage.  I think that the wood will shrink
away from any exposed edge, so as the wood shrinks away from the bolt
hole, the hole will get bigger.



Kipp A. Martin, P.E., S.E.
Carollo Engineers
503-227-1885
503-227-1747 (fax)
kmartin(--nospam--at)carollo.com

>>> gmadden(--nospam--at)maddengine.com 3/2/2006 9:41 AM >>>
Never watched a donut shrink. so I'll take your word on it. Ok, strike
that one out for a reason. :-)
 
-gm
 
-----Original Message-----
From: Garner, Robert [mailto:rgarner(--nospam--at)moffattnichol.com] 
Sent: Thursday, March 02, 2006 9:29 AM
To: seaint(--nospam--at)seaint.org 
Subject: RE: 3X Plates and Washers on Intermediate Anchors
 
Shrinkage will decrease the hole diameter.  When a donut shrinks, does
the hole get bigger?
 
  _____

From: Gerard Madden, SE [mailto:gmadden(--nospam--at)maddengine.com] 
Sent: Thursday, March 02, 2006 9:17 AM
To: seaint(--nospam--at)seaint.org 
Subject: RE: 3X Plates and Washers on Intermediate Anchors
 
I know that the allowable values in the code are based on testing. I
would think that the clamping force from the nuts with plate washers
greatly contribute to the capacity. If there weren't any nuts, the
walls
would slide and bang ever so slightly back and force because the holes
in mudsill will not be snug and with shrinkage, the holes size will
increase over time.
 
-gm
 
-----Original Message-----
From: Bill Allen [mailto:T.W.Allen(--nospam--at)cox.net] 
Sent: Thursday, March 02, 2006 9:02 AM
To: seaint(--nospam--at)seaint.org 
Subject: 3X Plates and Washers on Intermediate Anchors
 
So, as I understand it, the requirements for 3X sill plates for shear
walls with Fv > 350 PLF (CBC Table 23-II-I-1, footnote 3) and square
plate washers (CBC Section 1806.6.1) on intermediate anchors are a
result of observations that, when wood shear walls lift (due to lack
of
restraint at the hold downs), the sill plate will tend to split. The
square washer distributes the load better and the thicker 3X sill
plate
will provide a better section to resist flexure. O.K., I understand
that.
 
Maybe these are two separate issues.
 
What about another solution? What if the nuts (and washers) were left
off entirely? It certainly seems to me that would eliminate the
requirement for the square plate washers (if none were required in the
first place). I'm not sure if this would be a remedy for the 3X sill
plates. I understand the requirement for 3X members at abutting panel
edges to reduce splitting, but I'm guessing the 3X sill plate
requirement is to reduce flexural failure. I'm sure I will be
corrected
if I'm mistaken.
 
All code references are to the 2001 CBC (sorry).
 
Just a thought. Comments are welcome.
 
T. William (Bill) Allen, S.E.
ALLEN DESIGNS <http://www.AllenDesigns.com>
Consulting Structural Engineers
 V (949) 248-8588 . F(949) 209-2509
 
The information contained in the e-Mail, including any accompanying
documents or attachments, is from Moffatt & Nichol and is intended
only
for the use of the individual or entity named above, and is privileged
and confidential. If you are not the intended recipient, be aware that
any disclosure, dissemination, distribution, copying or use of the
contents of this message is strictly prohibited. If you received this
message in error, please notify us.
	

******* ****** ******* ******** ******* ******* ******* ***
*   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 
******* ****** ****** ****** ******* ****** ****** ********