You are correct to it being an egotistical shock since I have never heard of this since my introduction to this fine field in '84. I know what the difference is in regard to 4 way bracing and where it is preferably required. If NFPA-13 explains or even mentions how to calculate prying force factors, then please educate me on its location. I have been doing quite a bit of work for DSA the last couple of years and have never been asked for it. Even when I was part of a team of 4 designers with simplexgrinnell working on the UCLA Medical Center in '01 or '02 i had never been asked it. I have never had the formal training like most of the fine gentlemen of this Forman. Just an old cook whose work injuries caused him to hang up his bags, go back to school and learn how to design (and wishing he was an engineer). I now learned today that Prying force factors do not even apply to my project because it is all steel I beams on metal decking. No concrete anchors at all, Thanks Ken for the input.
P.S. Steve you are correct about the estimated time for design and have only made that mistake the first time I designed a DSA Project (Nearly impossible for to get an exact estimate of time with out some cohesive set standards). Thanks, George Medina Jr. -----Original Message----- From: Steve Leyton <[email protected]> To: sprinklerforum <[email protected]> Sent: Mon, Sep 17, 2012 9:51 am Subject: RE: 4-WAY BRACING INCLUDING PRYING ACTION ON FASTNERS PER OSHPD'S OPA#601 Okay you kids, don't try this at home without adult supervision. George, you're LA-based? I'm surprised that you are encountering this for the first time. If you've been following the forum for at least a few months, I believe a while back I made the comment on a similar topic that our library of hanger and bracing details now looks very similar to, and contains content that is equivalent in many cases to documents you would expect to see from a structural engineer. We've been doing a fairly high volume of OSHPD and DSA work for the past 4+ years and I think we have them more or less sorted out. I'm assuming you're working in the LA office of DSA, as they have a lot of former OSHPD plan reviewers on staff and are pretty romanced by the OSHPD design manual. But here's the thing: they're not asking for anything that isn't either in or implied in NFPA 13. The basis of the design in question can be found in ASCE 7, the civil engineering standard for Minimum Design Loads for Buildings and Other Structures, and which is the prescriptive basis for all building system seismic protection, including plumbing, mechanical, fire protection, etc. You don't' just go through fire/life safety plan review in these agencies, you are also subject to structural engineering review just as surely as the structural plans themselves. If you're not familiar with their practices and the intensity of their reviews, it can be a shock. We've all had that egotistical reaction when an AHJ requires something that we've not seen or done before ("What?? I've been in this business 25 years and I've never had to do THAT before!") But the bottom line is that they are asking you to do the seismic bracing calc's and details in exact conformance to ASCE 7 - as prescribed in the CA Building Code and referenced in NFPA 13, including the net vertical reaction force as prescribed in 9.3.5.7. This section is not new in the current standard - was added in 2007 if I recall correctly. As for whether it's a "four-way" or a location where both lateral and longitudinal braces are applied, I think that might be a case of to-MAY-to vs. to-MAH-to. Keep in mind that the standard offers options with regard to bracing vertical piping, including the main riser. You can put a 90 deg. "four-way" on the pipe and brace to a structural wall as has been done conventionally for years, but you can also use a lat and long at the top of the riser, attached to the piping after it turns horizontal. The bottom line is that we SHOULD have been doing this all along. And any of y'all out there who might be considering a design in CA with one of these agencies for the first time, if you haven't doubled or tripled your budgeted hours, my friendly and unsolicited advice is to take another look at your estimate worksheet. Steve Leyton -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, September 16, 2012 8:02 PM To: [email protected] Subject: Re: 4-WAY BRACING INCLUDING PRYING ACTION ON FASTNERS PER OSHPD'S OPA#601 George, I have never had to, am away from my desk, and would rather not aswer a question with a question, or be overly general, but I would like to know the extent of your problem-- how many "risers" (vertical pipes) do you have to brace? I have to admit I think there is some confusion on what a 4-way brace is, since some manufacturer's details call (2) 2-way brace AT THE SAME LOCATION a 4-way. The Forum please correct me if need be, but I think a 4-way is only for vertical pipes, and if so, your task might be lessened, once someone with some experience replies. Quoting Steve Leyton <[email protected]>: > CA - where else? > > Steve > > Bruce Verhei <[email protected]> wrote: > > George > Which State? > Bv > > Sent from my Motorola ATRIXÂ(tm) 4G on AT&T > > -----Original message----- > From: George Medina Jr <[email protected]> > To: [email protected] > Sent: Sun, Sep 16, 2012 22:20:50 GMT+00:00 > Subject: 4-WAY BRACING INCLUDING PRYING ACTION ON FASTNERS PER OSHPD'S > OPA#601 > > > > > Has anyone had to provide prying action factors to seismic > calculations for the Department of State Architecture. I have been > requested by DSA to:'Provide calculations showing 4 way brace > connections to take ZOE loads per NFPA 13 Sec. 9.3.5.5.3 and include > prying action on fasteners per OPA > 0601 p. 5.4' . I have attached the sheet from the document and have to > be totally honest that I have never had to provide this before. I use > AFCON's Bracing Calculation Program and would like to know if I am > going to have to end up doing the calculation by hand to add the prying factor. > If someone can briefly explain how the prying factor works I would be > indebted to thee for the rest of my short natural life. > I could send a copy of Sheet 5.4 of the OPA #601 to anyone that can help. > > Thank You, > George Medina Jr. > > > > > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: > <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/atta > chme nts/20120916/957ee066/attachment.html> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: > <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/atta > chme nts/20120916/c0b35847/attachment.html> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum -------------- next part -------------- An HTML attachment was scrubbed... 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