Just one bolt?
Just one bolt?
(OP)
OSHA/AISC requires one bolt in solid webbed bracing members for erection purposes, but can the final connection only utilize one bolt? I don't like the idea of any connection relying on one bolt, but this is not my design... just a review. I've searched this site, the web and the AISC manual and cannot find anything stating that more than one bolt is required for bracing connections. (FYI - the bracing is concentric tension only X-bracing using single angles)






RE: Just one bolt?
RE: Just one bolt?
If I was reviewing someone else's design and saw only one bolt in the connection you describe I would definitley question it, and offer my preofessional opinion that the connection should have multiple bolts.
RE: Just one bolt?
During the final placing of solid web structural members, the load shall not be released from the hoisting line until the members are secured with at least two bolts per connection, of the same size and strength as shown in the erection drawings, drawn up wrench-tight or the equivalent as specified by the project structural engineer of record, except as specified in paragraph (b) of this section.
RE: Just one bolt?
RE: Just one bolt?
DaveAtkins
RE: Just one bolt?
RE: Just one bolt?
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RE: Just one bolt?
Thank you all for your responses.
RE: Just one bolt?
If only one bolt is used, the ironworker has to spud the hole, use a "c" clamp to clamp the iron tight, remove the wrench and then hope the clamp holds the alignment until the bolt is place. It is false economy to use one bolt. The extra bolt hole saves time and money.
Best regards - Al
Best regards - Al
RE: Just one bolt?
After that, I used 2 bolts in my all other design.
RE: Just one bolt?
RE: Just one bolt?
Depending on what code is applicable to your project, what you have may or may not be okay. Letter of the law versus spirit of the law.
RE: Just one bolt?
Personally, I think 1 bolt is fine for light loads: I mean it is supposed to hold thousands of pounds. But more importantly, a single bolt is predictably a pin... no moment development to force unforeseen loads into the bolt. With two bolts, and a 3" eccentricity, you get like an effective capacity of like 1.1 bolts or something. That seems pretty darned inefficient.
So, if you're concerned about redundancy, and lawyers, and things of that nature, sure, throw a 1.5 FS on it, but at least with one bolt, you know you just have a pin.
And I think you can probably find a long history of single pin connections with clevises and whatnot. Fact is, the brand new seismic system for the 2006 IBC, Buckling-Restrained Braces, those use single-pinned connections (as manufactured by Star Seismic). Although... those are like 5" diameter pins in some cases. :)
Cheers,
Mike
RE: Just one bolt?
RE: Just one bolt?
Regards,
Mark
RE: Just one bolt?
It says angles
Just as a note:
A bolt in this case will be subject not only to shear but also to the prying force due to the exentricity of the centre line of the angle.
And the instalation. Few good ppoints were made here regarding this. Thanks Men. Verry verry good ones.
Use 2 bolts and have a nice dreams.
Y
(to get it right assume you are wrong)
RE: Just one bolt?
http://
I wonder if these were chinese bolts in this chinese crane?
rmw
RE: Just one bolt?
I had a good laugh with this article. Here's a quote from the article:
"They're not the wrong bolts. They just don't meet specifications for the crane."
hahahaha yeah right!
RE: Just one bolt?