Dan, I agree with almost all of that, with a couple of minor exceptions.
-NFPA uses the Design Category for how to apply its rules (none, '02, or '07/'10) including if b-line restraint gets factored in along with sway brace. NFPA-13 makes no distinction as to *when* seismic protection is required, but only how it is to be installed. The determination of "when" is from either ASCE7-05, or the IBC (CBC if you're in California). Further, the requirements for seismic protection include all of section 9.3 of -13, not just bracing or restraint. That includes flexible couplings, clearance, seismic joint assemblies (like Metraflex), bracing, restraint, and some modifications to hangers. AFSA has an excellent online class explaining all of that stuff. It really helped me get a better understanding of all of that. Additionally, I looked at the great reference you provided from NSICC, and the only difference I'd suggest to anyone using it to determine the Ss (more on that in a moment) is to use the ASCE7 method, rather than the NEHRP method to determine those values. Having said that, let me insert here a well thought out rant at structural engineers who don't provide this information on plans transmitted to sprinkler contractors. There is no reason we should ever have to do this kind of work, because it's very clearly not our responsibility. Sure, like everyone else out here in the land of the rolling ground I've had to figure these values out while I waited for a structural to do their job, and the ability to understand those numbers and apply them correctly is of real value out here. I don't do structural engineering, he doesn't do fire sprinkler system design, and that's the way I like it. There, I feel better. again, NFPA committee member disclaimer.... -- PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [email protected] <mailto:[email protected]> e-mail www.ParsleyConsulting.com <http://www.ParsleyConsulting.com> website Daniel Wilder wrote: > I thought (here, here for a test) > -Site class was based on soil conditions (A-F, good to bad) > -Occupancy category was the importance of the building after an incident > (I-IV, i.e. guard house vs hospital. > -Design Category uses the Site Class & Occupancy category information to > come up with the "A-D" (little protection to heavy seismic consideration) > -NFPA uses the Design Category for how to apply its rules (none, '02, or > '07/'10) including if b-line restraint gets factored in along with sway > brace. > > All should be shown on the front page of the Structural drawings. > > You can download the USGS info here > http://earthquake.usgs.gov/hazards/designmaps/javacalc.php > which gives you the site class, SS values, and lots of other "can I buy a > vowel" acronyms based on the lat/long of the site. > > The occupancy & design category is out of the building codes... > > This also might help to understand the process: > http://www.nsicc.org/PDF_Files/Seismic%20Design%20Category%20_06%20IBC_.pdf > > D > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Dewayne > Martinez > Sent: Thursday, June 24, 2010 2:11 PM > To: [email protected] > Subject: RE: seismic design category > > Is the site class used to determine the design category? > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Thursday, June 24, 2010 4:00 PM > To: [email protected] > Subject: RE: seismic design category > > Design category is your deciding factor. For an "A" category you should > have to do nothing special. > > But, a few years ago we had a similar situation with concrete anchors so it > could be an owner standard requirement not necessarily based on seismic > issues. > > Craig L. Prahl, CET > Fire Protection Specialist > Mechanical Department > CH2MHILL > Lockwood Greene > 1500 International Drive > Spartanburg, SC 29304-0491 > Direct - 864.599.4102 > Fax - 864.599.8439 > [email protected] > http://www.ch2m.com > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Dewayne > Martinez > Sent: Thursday, June 24, 2010 4:55 PM > To: [email protected] > Subject: seismic design category > > What is the difference between the "seismic site class" and the "seismic > design category"? > I have an engineer who is making us install "cracked concrete approved" > inserts based upon > a seismic site class C. The structural drawings also show a seismic design > category A. > I thought that the design category is what we use to determine if seismic > hangers are required? > Here is Wisconsin we don't see this so this I am a bit confused. > Thanks, > Dewayne > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > > _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
