# NCEES Practice Problems



## Wood (Oct 2, 2008)

It's been awhile since I've done some statics problems and this particular question is stumping me. I understand that the dead and wind contribute to the overturn and uplift, but why not the live load? Please help! It's driving me crazy!


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## Minhas (Oct 2, 2008)

Wood said:


> It's been awhile since I've done some statics problems and this particular question is stumping me. I understand that the dead and wind contribute to the overturn and uplift, but why not the live load? Please help! It's driving me crazy!


The reason we do not include live load in design for upllift and overturning is because live load might not always be there to resist.

Also, keep in mind that question is not asking what would contribute to the uplift and overturning. Question is asking what would RESIST overturning and uplift. So both live load and wind load are out. The answer is A (Dead load only)


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## Wood (Oct 2, 2008)

The answwer key says the answer is C - wind and dead load. So are you saying the answer key is incorrect? Because if so, I understand your explanation. But that's not what the booklet says is the correct answer


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## Casey (Oct 3, 2008)

I checked my book last night and the question is asking "To design the footing for overturning which load cases should you consider?" It does not ask which forces are resisting overturning.

So in this case the answer Dead and Wind is correct.

The wind load is the cause of the overturning action and the dead load resists overturning. We do not include live load, because as Minhas said we cannot be certain that the live load will be present at the time when the wind load induces overturning. Another way of looking at it is that having only dead load resisting the overturning can be regarded as your worst case scenario.

I hope this helps.


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## Wood (Oct 3, 2008)

Casey said:


> I checked my book last night and the question is asking "To design the footing for overturning which load cases should you consider?" It does not ask which forces are resisting overturning.
> So in this case the answer Dead and Wind is correct.
> 
> The wind load is the cause of the overturning action and the dead load resists overturning. We do not include live load, because as Minhas said we cannot be certain that the live load will be present at the time when the wind load induces overturning. Another way of looking at it is that having only dead load resisting the overturning can be regarded as your worst case scenario.
> ...


There we go! Thanks. I really have to make sure I read those questions carefully. Thank you so very much! Great explanation!


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