Applying EQ forces on liquid containing tank 1

[Robbiee]

How do you apply earthquake force on liquid containing steel tank such as the one shown in the attachment? Which one of the three, if any, is correct?
Thanks

 

[JStephen]

There's no attachment.

 

[Robbiee]

OK, I committed another mistake, by starting a new thread for the attachment only. Is it the Friday effect?
Anyway, here is the attachment and, Moderator, please delete the other thread for me.
Thanks

 

[spats]

I don't know what code you're working with, But ASCE 7-05, Section 15.7 covers tanks and vessels. You also need to take int account the effects of sloshing.

 

[IFRs]

API 650 has sections on seismic loading, including overturning, increased shell stress, foundation loads, etc. Is this an API, AWWA or other code tank?

 

[Robbiee]

I am in Ontario Canada. The code is the Ontario Building Code.

 

[IFRs]

The API methodology is applicable to any location

 

[JoshPlumSE]

Take a look at ACI 350.3 and the commentary.

You actually have to account for both the impulsive (weight of tank) and convective (weight of fluid) loads in your tank analysis.

There is a good PCA pamphlet / design guide on the subject that should help.

http://www.cement.org/bookstore/profile.asp?itemid=EB219

Granted this is written for the US codes. But, I the basic concepts and theory should allow for a relatively easy translation to the NBCC seismic forces.

Josh

 

[IFRs]

API 650 equations do impulsive and convective. The theory is the same. API simplifies the methods to a level such that even I can run the analysis. It is AST specific and so cuts through to what is really needed and leaves out the rest. Disclaimer: I do not work for API but I use their codes daily.

 

[JStephen]

I'm not familiar with the Ontario building code. But it seems that building codes in general do a very poor job of addressing tanks, which is one reason to refer to tank standards specifically. There are standards for welded steel, bolted steel, concrete tanks, etc., and all are based on similar methods. If your tank falls under any particular standard, refer to that standard for seismic design.

For very small tanks that might not normally be designed by these methods, the design load would be a point load at the center of mass of the combined tank and fluid.