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Wall anchorage to steel deck

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Some time ago I designed a CMU wall building with steel joists and a metal
deck diaphragm in LA County.  The plan check required that I detail the
side wall anchorage (the walls parallel to the direction of the steel
joists) in the same manner as is required for wood roof diaphragms.  She
limited my subdiaphragm shear to 250plf also.  I created subdiaphragms
using steel angles at 4'-0" o.c. as substitutes for subpurlins.  The
angles were located directly under the metal deck, were bolted into the
CMU wall, and extended into the roof diaphragm a distance equal to the
calculated subdiaphragm depth.  The steel deck was puddle welded to the
steel angle struts at 6"o.c.  Steel angle-to-angle ties were provided
where the struts intersected with the joists.  Cross-wall continuity ties
were provided at 24' o.c. and were either the joist girder top chords or
double angle struts similar to the subdiaphragm struts.  This approach
seems reasonable to me since steel deck diaphragms are flexible diaphragms
similar to the wood deck diaphragms.  However, I am puzzled because I do
not see this kind of detailing being performed on the single story, steel
deck flexible diaphragms currently being constructed in my community,
south Orange Co.  I was wondering what other engineers were doing
regarding the anchorage of masonry or concrete walls to steel deck
diaphragms.  Why is this type of subdiaphragm detailing required in some
locations but not in others?

Chris Harris