If the bottom chord is in compression from net uplift then you want to have
the bottom chord ends braced.
-----Original Message-----
From: Harold Sprague [mailto:spraguehope@hotmail.com]
Sent: Tuesday, September 25, 2007 1:54 PM
To: seaint@seaint.org
Subject: RE: Joist girder stabilizer plates in existing building
Andrew,
You are correct. When there is wind uplift the entire bottom chord is in
compression requiring bracing in some fashion. The truss diagonal elements
will be in compression or tension in a gravity load or with a wind uplift
load. Since the web / truss diagonals will compression elements, they will
require bracing.
Regards,
Harold Sprague
________________________________
From: akester@cfl.rr.com
To: seaint@seaint.org
Subject: RE: Joist girder stabilizer plates in existing building
Date: Tue, 25 Sep 2007 12:17:30 -0400
Aren't roof joist girder stabilizers there for the same general
reason that continuous bottom chord bracing for joists are supplied, for
uplift wind pressure loading? Like Harold said, this puts the bottom chord
into compression and unlike the top chord that is braced by deck the bottom
chord needs to be braced. There would also tend to be rotation and movement
at the ends, thus the stabilizer plate.Something intuitively says the plates
also help in gravity loading to keep the bottom chords from "kicking out". I
am not a joist designer so I stand to be corrected..
Andrew Kester, PE
Principal/Project Manager
ADK Structural Engineering, PLLC
1510 E Colonial Ave., Suite 301
Orlando, FL 32803
________________________________
Make your little one a shining star! Shine on!
<http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=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@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
******* ****** ****** ****** ******* ****** ****** ********