Subject: Re: For Urgent Review and Comment - Blue Book Commentary
Date: Sun, 23 May 1999 13:29:07 EDT
I believe an area limitation, below which consideration of the rigidity of
the diaphram need not be made, would be appropriate much like the limitation
for Conventional Construction at least until we have better tested
information on how to analyze and quantify the rigidity of the various
assemblies of wood diaphrams.
Another idea would be to limit the shear wall stress to 1/2 values (similar
to uninspected masonry) if a rigid diaphram analysis is required but not
elected to be performed.
These ideas are put forth in order to keep the computational effort required
for most single family residences, condominiums, or small limited occupancy
structures comensurate with the fees an engineer may realistically expect to
receive. The benefit to cost ratio of a rigid diaphram analysis is
questionable, and further may not more accurately predict the response of the
structure due to a number of reasons unrelated to our computational abilities.