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RE: Input with regard to section 1633.2.4

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REgarding the following "snip",

The '97 UBC has changed this deformation compatability value to 0.7R(Delta
s) where (delta s) is the calculated drift and R is the new seismic
"reliability" coefficient. As an alternate you can also use 0.0025h where h
is the story height for the level that you wish to examine.  For a shearwall
building R=5.5 so your minimum drift would be (3.85* delta s).
Alternatively, if your floor to floor height,h, is 10', drift would be

The deformation that you calculate is then applied to the element(s).  The
resulting moments and shears need to be accommodated in your design so that
the joints do not fail during a seismic event.  For columns you also need to
check the Pdelta effects (moments due to incresed eccentricity).  For
Concrete columns and beams this usually means that you place ties at 4"oc
for ductility and verify that the increased eccentricity does not blow your
column out.
For concrete columns, you don't have to actually design for the moments and
shears resulting from the delta-M displacement.  The ACI (and UBC) says that you
check if the moment and shear strength is less than the imposed forces.  If the
strength provided is less, then ductile detailing, basically closely-spaced
confinement ties, are required.  Otherwise they are not.

regards, Martin

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