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pretensioned HS bolts

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Hello,

I am hoping to get some input or guidance from all of you structural steel
experts about the use of fully-tensioned or slip critical, high
strength(A325SC or A490SC)bolts. I have always specified them for use on all
seismic connections including drag lines and any joints subject to direct
tension, but I'm noticing that other engineers don't do this.  
According to the RCSC Specification for Structural Joints Using A325 or A490
Bolts, SC bolts should be used for joints "subject to significant load
reversal", and "joints in which, in the judgement of the Engineer, any slip
would be critical to the performance of the joint or structure..".  Do these
apply to seismic resisting systems (or wind)?  In FEMA 350 and AISC Chapter
4, the bolted MF connections show use of "pretensioned" bolts, however, in
the HSS manual Moment connections, I don't see mention of tensioning the
bolts.  
In regard to the direct tension connections, Chapter J in the AISC ASD
manual (Table J3.2)indicates that the allowable tension for a high strength
bolt is independent of the intial tightening force (listed as 44 ksi for
A325 and 54 ksi for A490); however, the RCSC specification (Table 2)
indicates that applied static tension allowables are only for pretensioned
bolts (footnote b).  ??


karen casano, PE 
san diego

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