Need a book?
Engineering books recommendations...
Return to index:
Component Amplification factor a.p
- To: <seaint(--nospam--at)seaint.org>
- Subject: Component Amplification factor a.p
- From: "Timothy P. Spengler" <timothyps(--nospam--at)cleanpak.com>
- Date: Thu, 11 Jul 2002 10:30:27 -0700
what could best be classified as a "structural" suspended ceiling grid.
It's similar to a standard suspended ceiling, except much stronger. The
system will be hung from a roof superstructure using 3/4" diameter threaded rods
and laterally braced with pre-stretched wire rope. The ceiling grid itself consists of 4" deep x 2" wide
aluminum extrustion tubes laid out on a 2' x 4' grid pattern and
will support, on average, 10 psf of self weight plus 12 psf of additional load
suspended for the ceiling. The ends of the aluminum extrusions will be
On the advise of another engineer, my client is dictating
that a component amplification
factor of 2.5 be used for the seismic design of this system. Upon
researching this item in the UBC and the California blue book I was able to
technically determine that my system had a fundamental period greater than 0.06
and could therefore be classified as a flexible component and require an
amplification factor of 2.5. However, there are numerous items in Table
16-0 of the UBC that closely match my system (such as suspended ceilings,
conduits and piping.) yet only require an amplification factor of 1.0.
In addition, the
blue book seems to indicate that the potential for seismic amplification
is reduced if a system is ductile, therefore resulting in a
amplication factor of 1.0. However, this is only mentioned once and I
would not consider it amble evidence to refute using an amplification factor of
My question to the
group is 1) Is there a more technically refined way that I could prove that my
system can be designed using an amplification factor of 1.0? and 2) Does anybody
know of any additional sources that have a more detailed discussion of parts and
portions seismic analysis?