Subject: Re: Seismic Upgrade.... Blue Book Commentary on wood diaphragm
Date: Sun, 23 May 1999 16:19:29 EDT
Williston "Bill" L. Warren, IV - S.E.
"It was clear from the damage of the Northridge earthquake that the simple
span or flexible diaphragm assumption, or half the width tributary area
assumption abeing supported by rigid supports was not correct."
For several weeks after the ensuing of this discussion I have wondered if
there were any documentation or verification that the assumption of diaphragm
flexibility was proven to be incorrect in the past earthquakes. According to
Mr. warren it was. If this is the case I believe those advocating the
diaphragm rigidity analysis for light framed wood structures owe it to the
rest of us to share this information. I am keeping an open mind on this
subject, but I like to see proof that this supposedly erroneous assumption
led to serious undesirable behavior in these types of structures in the past