Need a book? Engineering books recommendations...

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

Re: R for a steel structure w/ equipments

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Ravi,
I don't have any knowledge about "Seismic guidelines for design of petrochemical
facilities."

If this guideline refer to UBC, we can use UBC TABLE 16-N. If your structure is
not included in the table, you can justify it based on Section 1629.9.2.

If this guideline doesn't refer to UBC, probably it provides the acceleration vs.
frequency or period load. Then you need to calculate natural frequency of the
structure, to calculate the corresponding acceleration, and to apply this force
without scaling. It means this guidelines doesn't allow the inelastic behavior of
the structure.

I hope my interpretation help you.

Chung-Soo

"Vasu, Ravi" wrote:

> Chung,
>
> I agree.  I have already selected a system(with connections) for this.
>
> What I am asking is the interpretation of UBC 1997 &
> " seismic guidelines for design of petrochemical faclities"
> by ASCE committee, section 4.2.3.2 for non building
> structure & section 4.2.4 for subsystem.   If we follow the above,
> do we have to select R per "seismic guidelines.... " or by
> UBC table 16-N(building/building like)?
>
> Thanks.
>
> Ravi vasu
>
> -----Original Message-----
> From: Chung-Soo Doo [mailto:CDoo(--nospam--at)sdesf.com]
> Sent: Tuesday, January 14, 2003 1:25 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: R for a steel structure w/ equipments
>
> Ravi,
> The "R" factor does not depends on what type of structure. The "R" factor
> can be justified by the "value" engineer.  As a value engineer, you can
> justify it considering the material and connection behavior of the lateral
> system.
> For example, OMF and SMF have same material but different connection
> detailing. Because SMF have more ductile connection detailing, it has higher
> "R" factor.
> This "R" factor is decided by overstrength factor and ductility factor.
> Therefore, you need to know both.
>
> For the further information, please refer "Blue book" or FEMA document.
> Probably you can find a good reference.
>
> Chung-Soo Doo
>
> "Vasu, Ravi" wrote:
>
> > I am sending this question again.  Can somebody look into this & give
> > comments?
> >
> > Please refer to the " seismic guidelines for design of petrochemical
> > faclities" by ASCE committee, section 4.2.3.2 for non building
> > structure & section 4.2.4 for subsystem.
> > 1. The question is what is the value of R for (a combined system) a steel
> > structure with platform &  supporting a small vessel & exchanger in
> > a two or three storied structure (30 to 40' height).
> > If it is a BUILDING (or building like) STRUCTURE, we use R from table 16-N
> > of UBC 1997.   Right?
> >
> > 2.  If the equipment wt. (one or more added toghether?)is more than
> 0.25(wt.
> > of the structure), do we need to (always) consider lower
> > R of the equipment and the structure ?  (appendix A, case 3 & 4)
> > irrespective of the height or area ?
> > I have seen big coolers/cooling towers supported on steel structure(cooler
> > covers most area of the structure).  I think only equipments like this
> > (& tall vertical vessel) fall under this category.)
> >
> > 3. It looks like, most of the structures supporting a vessel/exchanger
> fall
> > in 'subsystems' (section 4.2.4). What is R for this?
> > Thanks.
> >
> > Ravi Vasu, P.E.,
> >
> >
> ============================================================================
> ==========
> > NOTICE - This communication may contain confidential and privileged
> information that is for the sole use of the intended recipient. Any viewing,
> copying or distribution of, or reliance on this message by unintended
> recipients is strictly prohibited. If you have received this message in
> error, please notify us immediately by replying to the message and deleting
> it from your computer.
> >
> >
> ============================================================================
> ==
> >
> > ******* ****** ******* ******** ******* ******* ******* ***
> > *   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
> > ******* ****** ****** ****** ******* ****** ****** ********
>
> ==============================================================================
> NOTICE - This communication may contain confidential and privileged
> information that is for the sole use of the intended recipient. Any viewing,
> copying or distribution of, or reliance on this message by unintended
> recipients is strictly prohibited. If you have received this message in
> error, please notify us immediately by replying to the message and deleting
> it from your computer.
>
> ==============================================================================
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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
> ******* ****** ****** ****** ******* ****** ****** ********
begin:vcard 
n:Doo;Chung-Soo
tel;fax:415-781-2718
tel;work:415-781-1505
x-mozilla-html:FALSE
adr:;;;;;;
version:2.1
email;internet:cdoo(--nospam--at)sdesf.com
fn:Chung-Soo Doo, Ph.D.
end:vcard