0.6 Dead + 1.0 Wind Load Combination
0.6 Dead + 1.0 Wind Load Combination
(OP)
Looking to see what others do for this situation. For the 0.6D + 1.0W ASD load combination, do you use 0.6 of full design dead load allowance, or do you use 0.6 of absolute minimum actual dead load? This isn't an overturning thing, it's a net uplift on roof thing.






RE: 0.6 Dead + 1.0 Wind Load Combination
RE: 0.6 Dead + 1.0 Wind Load Combination
I don't think the code is particularly clear on it. Personally, I try and use as realistic estimate of dead load as I can.
The 10% overestimate argument does make sense to me though. 0.9 / 1.5 SF = 0.6. It's my understanding that the 1.5 safety factor is implied for overturning with the equation. Makes sense to me to extend this to uplift as well.
RE: 0.6 Dead + 1.0 Wind Load Combination
RE: 0.6 Dead + 1.0 Wind Load Combination
RE: 0.6 Dead + 1.0 Wind Load Combination
You don't get the reduction in overturning when checking soil bearing with this combo, but I think it yields a more realistic soil distribution if your design DL are not over done.
If you're working toward stability and using the footing weight for a resisting moment, I feel the 0.6D is too conservative for the self weight of the concrete even when thinking about vertical accelerations in combination with lateral accelerations.
RE: 0.6 Dead + 1.0 Wind Load Combination
Brian C Potter, PE
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