SEISMIC CALCULATION OF STORAGE TANKS AS PER API 650 1

[Anand23404]

Hello there!
Greetings for the day!
I have been thinking for a while about this and hence putting it before you for my better understanding.
Refer Annex-E (Seismic Design of Storage Tanks):
What is the meaning of "The Design level Peak Ground acceleration parameter (Sp)and what is the unit of this value. What does %g implies?
Take one case, Suppose the value of Sp is 0.36g, then either it means that this equals to 0.36 m/s2 or if it means 0.36 x 9.81 m/s2?

And for my Indian seniors out there, please tell me one thing. How can I relate 'Peak ground accn'(Sp) to Indian Zone factor(z)?

Your positive response will be highly solicited.

regards

 

[12345abc6ttyui67]

I can't speak to what the Sp parameter is, but "units of 0.36g" definitely means 0.36 x 9.81m/s^2.

 

[IFRs]

In E2.2 you will find the definitions for the variables use.
Curiously all the "S" parameters except Sp are defined as %g.
Sp should be %g also.
This should also be evident in section EC where sample problems are worked out.

 

[WARose]

Peak (or maximum) ground acceleration(s) in codes like the IBC and so on, are the maximum design accelerations during a expected seismic event. They are normally given as a fraction (or percentage) of gravity. In the case of a metric PGA it would be PGA= (a/9.81)x100% (Where a= acceleration [in m/s[sup]2[/sup]) Which is typically the charted number in codes like ASCE. In the case of 0.36g, yes, it would equal 0.36*9.81.