Load Cases Versus Load Combinations

[AMiller]

After working through a couple NCEES Structural Depth Problems last night, I wanted clarify something. Often, they have a loaded beam and they list the loads as DL and LL. As the test taker, what should I be looking for to determine whether or not the loads should be put into load combinations or just used exactly as listed? So far I have not run into any that need load combinations so I don't have any comparison. Thanks for the input.

-Andrew Miller

 

[MA_PE]

After working through a couple NCEES Structural Depth Problems last night, I wanted clarify something. Often, they have a loaded beam and they list the loads as DL and LL. As the test taker, what should I be looking for to determine whether or not the loads should be put into load combinations or just used exactly as listed? So far I have not run into any that need load combinations so I don't have any comparison. Thanks for the input.
-Andrew Miller

I'm not sure I understand your question. In a typical problem the laods to be applied for the problem are clearly defined. The dead (DL) and live (LL) load designations define the type of load so you know what load factors to apply to that component when the loads are applied. I would always assume that the loads are combined in the manner that the referenced code requires, unles the problem specifically states something like "what's the dead load deflection?", where live load effects are not to be considered for that exercise.

I hope that helps.