I have been sort of following this wind discussion and wonder if you
could enlighten me. Since we don't use your codes, I am wondering what
it is about these new ASCE provisions that has got all your knickers in
a knot. Can you send an example or copy of the particular section. If
it is too big, don't bother. I am just curious.
Gary
Haan, Scott M POA wrote:
> I just put it in my spreadsheet after reading some of the posts on this
> thread. The code is supposed to be a cook book not a puzzle.
>
> -----Original Message-----
> From: chris.slater@gmail.com [mailto:chris.slater@gmail.com] On Behalf Of
> Chris Slater
> Sent: Thursday, February 14, 2008 3:40 PM
> To: seaint@seaint.org
> Subject: Re: IBC 2007 Wind calcs.
>
> Right. I account for that by calculating a 10 psf load (that's the W1-10,
> W2-10, etc) and if that's greater than what I come up with by the other
> method, I use it.
>
>
> On Thu, Feb 14, 2008 at 4:03 PM, Haan, Scott M POA
> <Scott.M.Haan@usace.army.mil> wrote:
>
>> If you read the guide - I think per ASCE 7-05 6.1.4.1 you are supposed
>> to use a minimum of 10 psf projected on the vertical surface when you
>> have no horizontal pressure component on the roof. I rest my case:
>> not as easy as the UBC.
>>
>>
>>
>> -----Original Message-----
>> From: chris.slater@gmail.com [mailto:chris.slater@gmail.com] On
>> Behalf Of Chris Slater
>> Sent: Thursday, February 14, 2008 2:46 PM
>> To: seaint@seaint.org
>> Subject: Re: IBC 2007 Wind calcs.
>>
>> All of this talk is making me worry that we're doing something
>> horribly wrong...
>>
>> I put up a sample of the way we're doing our wind calcs here:
>>
http://www.examplecalcs.com/hosted/18329.pdf
>>
>> I use a program to generate the A, B, C and D loads. If the B and D
>> loads are negative, I just use 0. Then I generate my wind loads by
>> taking the B pressure from the ridge down to the plate, and the A
>> pressure from the plate to the middle of the wall height. In the
>> example I posted, W1 and W2 are calculated that way.
>>
>> For gable ends, or lower levels, I just use the A load from the top
>> of the projected area to the middle of the lower wall, which is how I
>> got
>> W3 and W4 in the example.
>>
>> For long buildings, I will sometimes use the C and D loads for the
>> section of the building that is more than 2a from the corners, but in
>> general, I just use the A and B loads since these tend to be lower
>> than the projected area winds we used in the old UBC code.
>>
>> It's not simple, but it's not incredibly complicated either. Which
>> makes me worried. Am I missing something, or does this seem like a
>> reasonable approach.
>>
>> Chris
>>
>> On Thu, Feb 14, 2008 at 2:58 PM, Haan, Scott M POA
>> <Scott.M.Haan@usace.army.mil> wrote:
>> > Scott.
>> >
>> > Compared to the UBC, all the ASCE 7 methods are more complicated.
>> I > agree with people who said use the analytical method for a rigid
>>
>>> building is the easiest way because there aren't 10 different zones
>>> etc... etc... but you still have to have a spreadsheet to calculate
>>>
>> the pressures.
>> >
>> > I think if I had to design a flexible building I would send
>> chocolate > cupcakes with turds in the middle to the ASCE7 wind
>> committee have a > supercomputer to calculate the gust factor.
>> >
>> > Scott.
>> >
>> >
>> > -----Original Message-----
>> > From: Scott Maxwell [mailto:smaxwell@umich.edu] > Sent:
>> Thursday, February 14, 2008 9:58 AM > To: seaint@seaint.org > > >
>> Subject: RE: IBC 2007 Wind calcs.
>> >
>> > I want to say that this method is more or less based off the >
>> simplified method that Washington has produce and has been mentioned
>> by others.
>> >
>> > Personally, while I find there to be some complexities that I
>> don't > feel are necessarily needed in the current ASCE 7 wind
>> provisions, I > don't find them that difficult to use...including
>> Method 1. I find > that I can pump out wind pressures in method 1 in
>>
> very short order.
>
>> > It does take more time to use those pressures to analyze stuff in
>>
>>> MWFRS since they now have corner pressures and such...but you don't
>>> really gain that much compared to older more "uniform" pressures >
>>>
>> except for some buildings that might be rather succeptible to >
>> torsional effects. But it does help that I have been using the ASCE
>>
>>> 7 methods for a LONG time, while engineers in CA are more used to
>>>
>> only using the simplified methods that were in the UBC.
>> >
>> > I would be the first to agree that ASCE 7 has gone of the deep end
>> to > some degree in "sharpening the pencil" for wind provisions, but
>> I am > not sure that I would liken them to a doctoral thesis (unless
>> you are > talking about the wind provisions for signs or flexible
>> structures or > dynamically sensitive structures and have to start
>> calculating gust coefficients).
>> >
>> > Regards,
>> >
>> > Scott
>> > Adrian, MI
>> >
>> > -----Original Message-----
>> > From: Matthew [mailto:sandman21@gmail.com]
>> > Sent: Thursday, February 14, 2008 12:48 PM
>> > To: seaint@seaint.org
>> > Subject: Re: IBC 2007 Wind calcs.
>> >
>> >
>> > You can also try using
>> >
>> >
>> http://www.documents.dgs.ca.gov/dsa/pubs/IR-16-7_WindLoad_12-18-07.pdf
>> >
>> > Matthew
>> >
>> >
>> > On Thu, Feb 14, 2008 at 9:34 AM, Paul Feather
>> > <PFeather@se-solutions.net> wrote:
>> >
>> >
>> > Stan,
>> >
>> > First off, the simplified method is anything but
>> > simple. We use the
>> > general method (method 2) for everything and get more
>> > consistent results
>> > easier. The simplified method is derived from metal
>> building
>> > manufacturer methods, and for anything but a metal
>> > building results in a
>> > complete book keeping atrocity.
>> >
>> > You are looking at 25 degrees area B. The way the
>> > simplified method
>> > works this is just one small area that cannot be
>> > applied in the same
>> > thinking as the UBC horizontal projected area. You
>> > have to add the area
>> > B to the Area E uplift, basically all areas A through
>> > H get applied
>> > simultaneously as one load case. Then you rotate the
>> > building reference
>> > corner and apply the whole thing again for all four
>> > reference corners.
>> >
>> > Get away from the simplified methods and you will
>> > simplify your life,
>> > while getting something closer to what you are used
>> > to. I don't believe
>> > the ASCE wind provisions could be any more convoluted
>> > and difficult to
>> > apply to real world engineering if we tried. The UBC
>> > methods were
>> > derived as a conservative simplification of the ASCE
>> > provisions years
>> > ago, and we desperately need to achieve something
>> > similar again.
>> > Spending three days on a doctoral thesis to develop
>> > simple wind
>> > pressures as opposed to working on load path and
>> > quality engineering is
>> > counter-productive, and saving 1.4 psf in wind
>> > pressure only matters to
>> > mass produced square boxes trying to be paper thin.
>> >
>> > Paul Feather PE, SE
>> > pfeather@SE-Solutions.net
>> >
www.SE-Solutions.net <http://www.se-solutions.net/>
>> >
>> >
>> >
>> > -----Original Message-----
>> > From: sscholl2@juno.com [mailto:sscholl2@juno.com]
>> >
>> > Sent: Thursday, February 14, 2008 9:09 AM
>> > To: seaint@seaint.org
>> > Subject: IBC 2007 Wind calcs.
>> >
>> >
>> > After 40 yrs. of doing UBC calcs. I am attempting to
>> > do my first IBC
>> > calcs. and need help, even after attending a seminar,
>> > which seemed to
>> > cover lots of things but not this.
>> >
>> > For a simple house, using 6.4 Method 1 Simplified
>> > Procedure, I cannot
>> > get a reasonable wind pressure of something between 15
>> > psf and 25 psf.
>> >
>> > From 6.4.2.1 <http://6.4.2.1/> , I get p s= 1.0 (1.0)
>> > 1.0
>> >
>> > (2.3) = 2.3 psf which is
>> > unrealistic. This is using Fig. 6-2, exposure B, h=30
>> > ft., Kzt =1
>> > and I=1
>> >
>> > Can someone point out my omissions/errors?
>> >
>> > Stan Scholl, P.E.
>> > Laguna Beach, CA
>> >
>> _____________________________________________________________
>> > Click for a credit repair consultation, raise your
>> > FICO score.
>> >
>> >
>>
> http://thirdpartyoffers.juno.com/TGL2111/fc/Ioyw6iifRtUze4Z9jymsCe1UDroI
>
>> > mKifm7vcAZ7s56ZSkSvbiqVDov/
>> >
>> <http://thirdpartyoffers.juno.com/TGL2111/fc/Ioyw6iifRtUze4Z9jymsCe1UD
>> > roImKif
>> > m7vcAZ7s56ZSkSvbiqVDov/>
>> >
>> >
>> >
>> > ******* ****** ******* ******** ******* ******* *******
>>
> ***
>
>> > * 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
>>
> <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@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
>>
> <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@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@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@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@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@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@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
******* ****** ****** ****** ******* ****** ****** ********