Spherical Vessel Seismic Loads 2

[HTCivil]

I'm looking for guidance on the proper determination of seismic loads on a spherical vessel. Specifically, I need the loads to size the foundation and anchor bolts.

I have experience with design of Above Ground Storage Tank foundations and am looking for an analog to API 650 Appendix E which provides detailed equations for the Convective and Impulsive components of the tank seismic load. I imagine that similar forces are at play on a spherical vessel and hope to find a document that spells it all out.

Any suggestions are appreciated.

Thank you.

 

[JStephen]

Refer to ASCE 7. I think generally, you'd treat all the contents as impulsive for a vessel.

 

[chicopee]

This is a paste and copy of the title of this particular article that I recently got from the internet. This should help. as an additional reference
"Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis, V. Plevris (eds.)Corfu, Greece, 26–28 May 2011
SEISMIC DESIGN OF SPHERICAL LIQUID STORAGE TANKS
(COMPDYN 2011) Matthias Wieschollek1, Maik Kopp1, Benno Hoffmeister1 and Markus Feldmann1
1 Institute for Steel Structures RWTH Aachen University 52074 Aachen, Germany
e-mail: wieschollek@stb.rwth-aachen.de"

 

[HTCivil]

Thank you for your input, I appreciate the help.

As a follow up, I began my search at ASCE 7-10, which states (section 15.7.12.4) that sloshing be considered in determining the effective mass of the stored material providing sufficient liquid surface exists for sloshing to occur. However, ASCE 7 provides no insight in how to properly determine sloshing accelerations of the liquid. Given that I may have cases where the tank is less than full, say 50% full, I wondered if there was literature on generating impulsive and convective components, hence my original post.

To JStephen's point, an option would be to simply design the foundation by treating all the contents as impulsive, which I believe would generate a conservative result. This lead me to consider that a full tank is certainly all impulsive, and of a magnitude likely considerably higher than the compulsive + impulsive components of a less than full tank, so maybe this all is a moot point. I do, however, value accuracy and would want a reality check on the assumption that to consider the convective component as impulsive is to generate a conservative result.

I appreciate the article posted by Chicopee. If anyone has any others, please post them as I would be interested in reviewing them. I found one also that I'll post to this thread in case someone else is interested.

Thanks again for the input.

 

[chicopee]

For sloshing effect, you may want to review the college course on fluid dynamics covering accelerated liquids in containers; now I never taken a seismic course,however, I suspect that seismic acceleration will be of the impulse type and that subject is covered in vibration courses.

 

[chicopee]

You got my curiosity peaked about sloshing within spherical tanks, so I found this article submitted by the ASME: Sloshing Effects on the Seismic Design of Horizontal ...

http://www.researchgate.net/profile/Spyros_Karamanos/...

There are numerous article sloshing from seismic events but the article that I have listed is probably more relevant to your inquiries.

 

[r6155]

See Pressure Vessel Design Manual 4th Ed. by Dennis R. Moss and Michael Basic

Regards
r6155