Help finding value in API 650 1

[LADYing]

Regarding the Equivalent Seismic Design Force and the Vertical Seismic Force (E.6.1.3), is the Weff simply the combined effective impulsive and convective weights calculated per E.6.1.1? If not, where is this weight defined? Also, I cannot find the lateral acceleration coefficient A for the equivalent lateral force calculation.

Thanks!!

 

[JStephen]

I think the definition of Weff would depend on the application. For total vertical force, it would include tank and contents. For compression in the shell, it would include the shell and roof supported by the shell. For loading on a ringwall, it would include the weight of tank and contents supported by the ringwall.

The "A" factor is not actually used as shown, that is the general relationship, and it is broken down into the impulsive and convective components using Ai and Ac as defined in E.4.6.2.

 

[LADYing]

Thanks a lot!! This page has been really helpfull for my thesis.