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RE: storage racks with partially restrained moment connections - wind frame analysis in high seismic zones

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In Southern California where I have worked for the past 20 years! Racks are
plan checked and also inspected by the building depts.

Code allows the building official certain latitude if racks are less than 8
feet tall. But if racks are taller than 8 feet most cities that I have
worked for required structural engineering calculations.

There are couple of companies in Southern Ca that mostly perform rack
designs one is called SEISMIC and its director Mr. Sal. He is very active in
various committees. There are other rack design firms in Glendale etc.

The racks have their own base shear formula in the 1998 CA code. The rack
foundation is also analyzed using beams on elastic foundation, or a
simplified method by Eugene Birnbaum is very poplar to deign footing for
racks. This method was accepted by LA County in 1986.

You are right Fire dept.'s also inspect racks . But they are interested in
the so called  IN Rack sprinklers and high piled storage provisions. For the
definition if the rack is more than 12 feet high its classified as high
plied storage. High piled storage requirements kick in certain fire safety
requirements for the building.

We have been basically using the SEAOC's blue book that was used a as the
back bone for UBC's structural provisions for years and years. We were to
use some more NEHERP provisions this year using the 2000 IBC , but IBC was
not adopted in California. The UBC and the SEAOC blue book are very clear on
their requirements for  design and inspection of racks and most major
metropolitan cities in Southern California that I know of adhere to these

-----Original Message-----
From: Sprague, Harold O. [mailto:SpragueHO(--nospam--at)]
Sent: Saturday, March 17, 2001 10:43 AM
To: 'seaint(--nospam--at)'
Subject: RE: storage racks with partially restrained moment connections
- wind frame analysis in high seismic zones

As a member of the BSSC TS 13, storage racks fall in my chapter of the
NEHRP.  This area has been a cause of concern and study.  But even more
fundamental to structural theory is how racks are used and approved.  Anyone
can take a rack originally designed and built for Dallas and assemble it in
the San Francisco area.  The inspection is a crap shoot.  If anything, the
fire marshal might inspect it to see if the racks are loaded within the
posted rating.  But whether or not the rack is in the appropriate Seismic
Design Category is neither generally posted nor generally checked.

This is an area that requires further study and work by the RMI and TS 13.

Harold O. Sprague