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Re: California Building Code seismic provisions.

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Charles

You may remember that the same time Central Section was exercising their
veto to purge Zone 2 from their back yard SEAOSD was exercising their veto
to keep San Diego Zone 3 when all of the evidence said it should be in Zone
4.   I am a little fuzzier on the history but their was also at one time a
proposal for a Zone 5 in parts of Northern California, that died because of
political considerations.

In the past there has been much complaining about the problems in the code
that resulted from individuals pushing their pet ideas.   Each of these
special provisions were justified  based on  "local conditions",
"protecting  public safety",  or making construction affordable.  The
problem has been that we end up with a code that has unintended
consequences.

I personally do not see much difference between the arguments put forward
in the past by SEAOCC and SEAOSD on zonation issues and the arguments put
forward by some of the proponents pushing their own pet ideas.

We can continue to modify the code in an adhoc manner in response to the
emotions of the moment or we can try to adopt a seismic code where 
provisions can be justified based on objective criteria.  Admittedly in the
past this was much harder and even now it is not easy.  In the long term I
believe that we will be better off if we focus on creating a model code
that provides a framework, based on objective cirteria, that allows us to
consider local conditions.

What is complicating this issue is that an individuals perception of risk
is not always related to the actual risk.  This is well recognized by those
who study risk.  The result is that in other parts of the country people
are probably under estimating the risk while in California we are more
(some whould argue overly) sensitive to the risk of earthquakes.   The real
problem is how do we create a code based on objective criteria while
recognizing that people deal with risk in a non objective manner.


Mark Gilligan