compression member finished to bear

[structSU10]

Does anyone here consider AISC 316-05 J1.4(b) for a beam supported on a cap plate? The provision is for compression members finished to bear, that are not columns. It seems somewhat appropriate due to fabrication tolerances of the wide flange and such, but I've also seen the argument that its not a compression member, and this applies to trusses. Any thoughts?

 

[Michel60]

Good morning structSU10,

Finish and milling requirements I believe apply when normal loading conditions would not otherwise bring surfaces to contact, e.g.- end of a column section and/or when not having a true surface would cause difficulty with erection or fabrication, e.g.- surface of a base plate. For what you describe I don't think the provision would apply. But that's not to say that it wouldn't be appropriate for some conditions say for a short, highly loaded beam that included transverse stiffeners. In that case the ability of the beam to come to contact would be reduced.

regards,
Michel

 

[Michel60]

...sorry I see now that wasn't the question you asked. Short answer still no, doesn't apply. Beam bearing on a seat is not a compression member. But some nominal connectivity force requirements for the beam to the seat should be considered, see ASCE7-05 12.1.4.

regards,
Michel