Subject: Re: Seismic Upgrade.... Blue Book Commentary on wood diaphragm
Date: Sun, 23 May 1999 22:30:15 EDT
In a message dated 5/23/99 3:30:38 PM Pacific Daylight Time, Byainc(--nospam--at)aol.com
<< 1- Your statement that the use of rotation was disallowed by the code
for multistory buildings may be more of a wishful thinking. The language in
the code for allowing rotation unfortunately has not changed for some time.
If you refer to the 7th paragraph of section 2315.1 in the 97 UBC the
is still allowed if you meet some dimensional and aspect ratio requirements.
The only reason you don't see more of these building being built, is that
most designers have the common sense of not opting for a scheme that has
proven to be problematic. Maybe this should be the focus of a future change
in the IBC which continues to allow this practice. >>
Thanks for the corrections, Ben. I don't remember the particulars but it
might have been a change in the Los Angeles City Code that outlawed open
front designs when a living unit existed above as a result of Northridge. It
might have occured earlier (Whittier Narrows or Loma Prieta) but I remember
the discussions that arose due to the change.
Possibly someone else can come up with the facts to support my memory. This
may have been restricted to the Los Angeles city and county.