Connection design LRFD or ASD?

[jakeh76]

What is everyone using for seismic connection design? The new provions have an ASD section our people using this or using the ASD? Thanks.

 

[pmkPE]

What do your clients or local governing authority require?

I prefer ASD. Why do extra calculations for (ultimately) the same answer. The main argument from my perspective was to save steel for large commercial projects that utilized similar size beams, configurations etc. I have seen savings measured in trade publications, especially by those promoting LRFD, as 1. to 3. percent. For very large commercial projects that may be justified savings. My clientele are mostly heavy industrial. We take into account additional effects of corrosive environments that those in the commercial arena do not have to account for. Sometimes, as in pulp and paper mills, the rule is Big by Heavy.

 

[TFL]

we require the fabricator to submit LRFD calculations using the uniform force distribution method in the LRFD manual. we allow them to design all standard shear connx in asd

 

[CSEllc]

Tecnically, the seismic loads are "LRFD" so if you want to be correct you should be doing your connection design in LRFD.

Typically, most connection design is ASD. The Seismic forces are"factored" down to alloawble loads and the design is based on those values.

I have designed the connections for several projects for different fabricators where the EOR specified the connection designed for 80% of the tension load of the HSS brace for example. So the ASD or LRFD value could be used.