wind loads

huangyhg

wind loads
a question about wind loading on a portable, vertical, cylindrical storage tank. the tank is not anchored and the concern is tipping of the empty tank due to wind forces.
i have calculated wind forces per asce 7-05, chapter 6, method 2.
is this the maximum wind force the the tank would be expected to see or should this force (and the tank dead weight) be factored per load combination 6 in par 2.3.2?
thanks for your help.
check out our whitepaper library.
combination 6 should cover you.  just make sure that if this thing is sitting on soil that the soil can handle it...
if you "heard" it on the internet, it's guilty until proven innocent. - dcs
i think you need to consider the likelihood the tank will be 100% empty when the maximum wind event occurs.  probably not likely to happen over the life of the tank.
don phillips
both you guys bring up good points.  and not only do you need to make sure that the soil can handle it but since it is a portable i would assume a low psf for the soil since it could be sitting on very different soils.  also the 100% empty strategy with the maximum wind event will be conservative analysis.
api (american petroleum institute) gives a procedure for this and is an acceptable approach to the computation.  i have not checked api vs. asce 7 since they are usually used separately for different reasons, but you might consider it since api deals with cylindrical storage tanks routinely, whereas asce 7 deals with them in a peripheral sense.  the american water works association (awwa) also addresses this issue for cylindrical ground storage tanks.
don't forget to check seismic for where you locate the tank.