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

RE: x-bracing connections

[Subject Prev][Subject Next][Thread Prev][Thread Next]
It's call "draw". Long, light angle bracing are relatively flexible
and tend to sag , vibrate, etc. This puts some pretension in them.
AISC used to recommend
up to 10 ft no deduction
10 ft to 20 ft deduct 1/16 in
20 ft to 30 ft deduct 1/8 in
I've seen bracing put in as Harold described many times and the
iron workers didn't seem to have any problems


Dick Roberts


> -----Original Message-----
> From: Sprague, Harold O. [mailto:SpragueHO(--nospam--at)bv.com]
> Sent: Tuesday, February 05, 2002 12:55 PM
> To: 'seaint(--nospam--at)seaint.org'
> Subject: RE: x-bracing connections
>
>
> Ron,
>
> X-bracing can be a problem, but is easily fixed.  Many savvy
> detailers will
> detail X-braces 1/8" short, and use 2 bolts at each end as a
> minimum.  Then
> the iron workers will drive bull pins (or drift pins
> depending on the iron
> worker regional jargon) in the outboard holes to line up the
> second hole and
> install the bolt.  The bull pin is then removed and the other bolt is
> installed.
>
> Another approach is to use over sized holes in the gusset and
> use a slip
> critical connection.  This is a good solution when you have a
> lot of bolts
> and claw angles where fit up can be problematic, but is over
> kill for only a
> little L 3x3x1/4 X-brace.
>
> Tell the iron workers that if they knew ANYTHING about
> hanging iron there
> should be no problem.  Oh yeah, then you need to run like hell!!
>
> Regards,
> Harold O. Sprague
>
> > -----Original Message-----
> > From:	Ron Hill [SMTP:ronhill(--nospam--at)hillce.com]
> > Sent:	Tuesday, February 05, 2002 11:32 AM
> > To:	Seaint@Seaint. Org
> > Subject:	x-bracing connections
> >
> > I have a client that says he has problems in the field with bolting
> > x-bracing.  The diagonals are generally 3x3 x1/4 angles
> bolted to gussets.
> > The holes are 13/16" diameter predrilled for 3/4" bolts.
> They claim that
> > the holes never align.  They want to maintain an all bolted erected
> > structure and welding the angle to the gusset is not an option.
> >
> > Has anyone had this problem with miss matched holes??  They
> claim the hole
> > locations are correct based on shop drawings but they think
> tolerances
> > cause
> > the problem.
> >
> >
> >
> > Ronald Hill, P.E.
> > HILL Consulting Engineering
> > PO BOX 26525
> > Birmingham, Alabama 35260 USA
> > Phone: 205.823.4784
> > FAX: 205.823.4145
> > Email: ronhill(--nospam--at)hillce.com
> > Efax: 509.275.8095
> > http:\\www.hillce.com
> >
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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
******* ****** ****** ****** ******* ****** ****** ********