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RE: "Sloshing Effects"

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Frank-
Most of the methods for liquid sloshing in tanks are based on work by George
Housner from the time period you state and earlier (e.g.,Housner, George,
"Dynamic Analysis of Fluids in Containers Subjected to Acceleration", ASCE
Technical Seminar: "Seismic Design Today - State-of-the-Art Applications",
January 25-26, 1980, Los Angeles).  Mehdat Haroun has extended some of this
work to include the flexibility of the walls (e.g, "Sesimic Design of Liquid
Storage Tanks", Preprint 80-085, ASCE Convention & Exposition, April 14-18,
1980, Portland) but the answers aren't greatly different considering that
the precision of the ground motion already has quite a variance.

The method by Housner considers the forces on a tank to be composed of two
components: an "impulsive" force with a short period based on a portion of
the fluid and the tank weight and a longer period "convective" force
representing the sloshing effect of the fluid.

AWWA D100 should provide you good guidance for design of water tanks.  For
petroleum tanks you may want to look at API Standard 650 which I understand
is based, or at least the version I have is based, on work by R. S. Wozniak
and W.W. Mitchell described in a 1978 paper.  Their work appears to be a
derivative work based on Housner's formulation.

One of the factors you need to be aware of, particularly for closed tanks,
is the effect of water rise due to sloshing.  It can play havoc with the
design of the roof structure.

Hope this helps

Regards,
Bill Cain, S.E.
Oakland  CA






"From the laying out of a line of a tunnel to its final completion, the work
may be either a series of experiments made at the expense of the proprietors
of the project, or a series of judicious applications of the results of
previous experience." 
 -H. S. Drinker in "Tunneling, Explosive Compounds and Rock Drills (1878).

 -----Original Message-----
From: 	Frank Griffin [mailto:fsg(--nospam--at)freese.com] 
Sent:	Tuesday, January 30, 2001 5:59 PM
To:	'seaint(--nospam--at)seaint.org'
Subject:	"Sloshing Effects"

Can someone guide me to any reference materials pertaining to seismic
effects of liquids in storage tanks?  UBC '97 makes mention of, "inertial
effects of the contained fluid."  IBC 2000 (which is the code in effect for
my project) makes mention of, "sloshing period of the stored liquid," and
states that, "The tank shall be designed to resist the effects of sloshing."
Furthermore, AWWA D100-96 states, "The design of ground-supported
flat-bottom tanks recognizes the reduction in seismic load due to the
sloshing of the contained liquid.  This design procedure is referred to as
the effective mass method."  There are some references in the Appendix, but
nothing more recent than 1984.  

Thanks in advance for any help you can provide.

Frank Griffin
Ft. Worth, Texas