Seismic Zone Anchoring 1

[Haldorson]

From what I understand sprinkler contractors in California use Hilti's Kwik-Bolt TZ expansion anchors almost exclusively for hanging pipe and sway bracing. The reason being it is listed for seismic zones while the popular Drop In Anchor is not.

In a seismic area, are we required to hang all the pipe and sway bracing using the Kwik-Bolt TZ (or equal) or just the mains? It seems like overkill for a 1" branchline, for example.

 

[TravisMack]

It is my understanding that if you are in concrete ALL anchors must be the Hilti TZ (or equivalent). But, seismic is not just in California. It is seen in a lot of different areas now. Look at your structural notes sheet in the contract set. If the seismic design category is C or higher, you need to get educated quickly on seismic.

http://eng-tips.com/viewthread.cfm?qid=362221

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Duwe6]

FYI, I don't let anybody hang anything using Drop-In's. Vibration makes them loosen up. Hilti's in tension just get tighter the more you vibrate them [ASSuming that the nut stays put]. Another one that works well in tension are the "gun nails" - powder actuated fasteners into steel. The grip is amazing, even in the overhead [fastener in tension]

 

[Haldorson]

What about cast in place anchors such as Powers Fasteners "Bang-It" concrete inserts?

 

[LowlySprnkLayoutTech]

Hilti Kwik-Bolt TZ seems to have the least embedment depth I have found. Only one that may be practical on some projects. Cost is about 4 times the wedge and sleeve anchors we were using.

Per NFPA 13, 2013 Section 9.3.5.12.7.1 (seismic since 2010?) and 9.3.7.8 (new for hangers in 2013) the key term is "prequalified.... per ACI 355.2" aka for cracked concrete. From what I understand it's a case of NFPA catching up to IBC/ASCE requirements.

9.3.7.8 says "Where seismic protection is provided, concrete anchors used to secure hangers to the building structure shall be in accordance with ACI 355.2, Qualification of Post-Installed Mechanical Anchors in Concrete, and installed in accordance with manufacture's instructions. This would seem to apply to all pipe sizes.

Spread the word, I'd hate to be the only dead hero.

 

[PRinspector]

Travis,
The link in your post goes right back to this post, is there another post with seismic information?

Duwe6
What are you mean when you say drop-in's?

regards

Lou

 

[TravisMack]

That was an accident in posting. Didn't mean to include a link.

I assume he is talking about Hilti HDI (hilti drop in anchor) or something similar. They are not listed for use in seismic areas, to my understanding.

We have used the cast in place anchors in seismic areas quite frequently.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Sdpaddler50]

Powder driven studs "gun nails" are no bueno. Take a look at a conc park structure with these and you will see many of these loose. When they are fired into conc, the conc can spall, and the stud becomes loose. FM won't accept them in EQ areas, and I believe LA City won't either. I am not sure what NFPA 13 says, because I have not checked lately.