Unbalanced Snow LRFD Combinations

[JoshH726]

Haven't seen threads addressing this, so I thought I'd throw out the following:

Reading through the exceptions to ASD and LRFD load combinations, I noticed that SD load combinations include unbalanced snow load with 0.5W, but reading the same exceptions for ASD load combinations, unbalanced snow is not combined with wind effects? So what gives? The commentary states that SD and ASD load combination 3 is intended to address unbalanced snow, but the SD combination includes 0.5W, where the ASD combination does not?

Perhaps a nefarious way to penalize LRFD proponents???

 

[TehMightyEngineer]

If I had to guess (and entirely a guess) they rationalized that to get an unbalanced snow load you need to have a strong wind and thus a wind load should be included. However, they didn't want to go and mess with the ASD load combos as much given their historical performance so they left them alone.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

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