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RE: (E) Masonry with steel upgrade

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Well, if you have enough strength, why don't you shave the wall to make it
thinner thereby increasing the steel ratio :o).

Bill Allen, S.E.
ALLEN DESIGNS
Laguna Niguel, CA


||-----Original Message-----
||From: merrick group [mailto:merrickgroup(--nospam--at)compuserve.com]
||Sent: Friday, January 21, 2000 11:04 AM
||To: Seaint
||Subject: (E) Masonry with steel upgrade
||
||
||I have an older building that has masonry
||steel ratios of .0008, .0009 and a total of
||.0017. I need .0007 min and a total of .002.
||
||How can I get this total ratio up?
||
||Can I allow the total number to be rounded
||up to 0.002? The code suggests a significant
||figure of one. I jokingly consider using the
||CMD97 program that allows the ratio.
||
||Shear capacities are from 1.5 times to 4 times
||that needed. Recall that the seismic-force-
||amplification-factor is 3.8. It would seem that
||adding extra reinforcement is unreasonable
||for capacity to demand ratio that is more than
||3.8.
||
||Without any good recommendations, I am
||adding some steel pilasters that can carry the
||tributary lateral loads out of the wall?s plane.
||I will consider the pilaster as equivalent to a
||vertical bar of steel, at that location, to
||increase the effective steel ratio. The walls
||already have masonry pilasters every 14 feet.
||
||Less than minimum steel has been considered
||as having an equivalent ductility of masonry
||with no steel. How silly. I am request that the
||Seismic-rulers-of-the-code to consider a
||reduced minimum steel ratio that is
||dependent on an application of an adjustable
||seismic-force-amplification-factor.
||
||David Merrick, SE
||Merrickgroup(--nospam--at)compuserve.com
||
||