Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Northridge Earthquake a Major "Event"

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Fred:

Unfortunately, this last posting of mine was not put in it's proper
context.  About 6 to 8 weeks ago, I was involved in a discussion with
others on the list about light wood framed one and two story wood framed
structures that were built using old codes, and or conventional framing
standards.  I was making trying to point that many one and two story
wood framed structures that did not come close to meeting today's code
performed adequately from a life safety perspective during the
Northridge earthquake.  I was using this as a way of showing light wood
framed structures have a proven record for using a flexible diaphragm
type analysis (or no analysis at all for that matter).  Someone, and I
do not remember who, took exception to this saying that the Northridge
earthquake was not a real test of a code level design quake, and further
went on to say that the quake is considered to be a "moderate" quake. 

Much time had passed, and I really had not added anything to this issue
since then.  Then I read the SEAOC blue book section on the Northridge
earthquake and saw the statement about the quake having large ground
accelerations.  So I jumped back into that very old conversation,
thinking that everyone else would also remember what I was talking
about.  My mistake.

For a system that relies heavily on ductility, I can see your point. 
But that is not what I was referring to.  My discussions was only
related to low rise wood framed buildings.  These buildings to have
ductility, but it is not something you inherently design for.  Wood
framed building exhibit non-linear behavior, and it is in fact some of
that kind of behavior that saved some of these buildings.  This type of
behavior in wood buildings is not well understood, and we do not design
these kinds of buildings taking this ability into account.

SO I STILL THINK I AM RIGHT!!  :)  At least in the limited context of
the original discussion.  For low rise wood framed structures, it is my
opinion that these structures were tested well for a Code design level
earthquake by the Northridge earthquake.  

You don't have to respond back, I should have clarified all this with my
first posting.  Sometimes I just don't understand why all of you just
can't read my mind!! :)

Lynn