Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Resultant Seismic Force

[Subject Prev][Subject Next][Thread Prev][Thread Next]

Industry practice is to apply the load at 2/3 height.  Reference ASCE Guidelines
For Seismic Evaluation And Design Of Petrochemical Structures, 1997.

Rick Drake, SE
Fluor Daniel, Aliso Viejo


"Vyacheslav Gordin" <scgordin(--nospam--at)> on 11/05/99 04:08:18 PM

Please respond to seaint(--nospam--at)

To:   seaint(--nospam--at)
cc:    (bcc: Rick Drake/AV/FD/FluorCorp)

Subject:  Resultant Seismic Force


Vertical cryogenic vessel (tank) on three legs in seismic Zone 4.

Diameter:      4-to-10 feet
Shell height:  10-to-50 feet
Leg height:     about 2 feet

Weight:          15-to-150 kips.

Should the resultant of the seismic force be located at:
a) tank center of gravity; or
b) at 2/3 of the height?

The opinion of fellow professionals is crucial for me making the decision to
either accept the method ?a? (customary for the industry), or try to push
through method ?b? (as ? in my opinion - more corresponding to the physical
nature of the problem).

So, what do you think?

Steve Gordin, S.E.,
Irvine, CA

P.S. Anyway, if we have something as simple as a CMU property wall ? where
would you apply the resultant of the seismic force?  SG

Get Your Private, Free Email at