Need a book? Engineering books recommendations...

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

Re: Drift Limits for Wind

[Subject Prev][Subject Next][Thread Prev][Thread Next]
IBC Table 1604.3 limits the deflection of exterior walls with brittle
finishes to l/240 for wind and seismic loads. Note that for cantilever
columns, l shall be twice the column length.

Violeta Tihova, P.E.
Silver State Code Consulting
1785 E. Sahara Ave. Ste. 157
Las Vegas, NV 89104
Ph: (702) 866-2633
F: (702) 893-2463


----- Original Message ----- 
From: "Scott Maxwell" <smaxwell(--nospam--at)engin.umich.edu>
To: <seaint(--nospam--at)seaint.org>
Sent: Wednesday, September 21, 2005 7:18 PM
Subject: Re: Drift Limits for Wind


> To elaborate on Paul's response, I would agree that "yes", you can design
> to "to meet L/240 for wind and the Delta_M for seismic".   You can design
> to what ever wind drift limit you want (at least as far as the code is
> concerned as I don't believe that there is any drift limits specified in
> the code for wind).  Now, will you be "OK"?  Dunno.  Depends on what the
> over all system (i.e. structural and non-structural items) can handle
> before problems occur.  As another poster suggested, to much drift could
> cause problems in your stucco finish (i.e. cracking, deteriorating, etc).
>
> But, the point is that the only CODE require drift limit is for seismic
> (that I am aware of).  Of course, "standard of care" might dictate some
> wind drift limits, but "standard of care" can be harder to interpret than
> code requirements.  ;-)
>
> Scott
> Adrian, MI
>
>
> On Wed, 21 Sep 2005, Paul Feather wrote:
>
> > Yes, unless the finishes require something more stringent than l/240.
> >
> >
> > Paul Feather PE, SE
> > www.SE-Solutions.net
> > pfeather(--nospam--at)SE-Solutions.net
> >   ----- Original Message -----
> >   From: Gerard Madden, SE
> >   To: seaint(--nospam--at)seaint.org
> >   Sent: Wednesday, September 21, 2005 4:13 PM
> >   Subject: Drift Limits for Wind
> >
> >
> >   I must be getting old cause I can't seem to find this, so I ask all of
you to refresh my memory..
> >
> >
> >
> >   I have a simple storefront renovation project and I am using
cantilevered steel columns to resist the lateral wind load. The wind force
governs over seismic by a factor of 2.
> >
> >
> >
> >   In UBC/CBC the Delta_M drift limit is 0.7*R*Delta_S .. Now that I know
for sure is for seismic and is straight forward.
> >
> >
> >
> >   Since I have twice the load governed by wind, do I still need to meet
this requirement?
> >
> >
> >
> >   I know technically there is no drift limit for 1 story steel
construction and this is basically a false tower/covered entrance outside of
an existing building but I'd still like to meet the drift limit since there
are several illuminated signage type things and stucco finish that I'd
rather not have bust all up under huge deflections.
> >
> >
> >
> >   Can I design it to meet L/240 for wind and the Delta_M for seismic and
be okay?
> >
> >
> >
> >   TIA,
> >
> >
> >
> >   -gm
> >
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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 
******* ****** ****** ****** ******* ****** ****** ********