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Re: Performance-Based Seismic Design, Potent

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Roger:

I believe there is a certain minimum requirement you are not allowed to go
below.  The categories are something like "life-safety", "controlled damage", and
"immediate occupancy".  These categories apply to seismic design.  The life
safety level is close to current code requirements.

Last time I looked, they were thinking of providing a numbering system of 1
through 10.  I think 10 was the highest level, which would be used on hospitals
etc.

I not sure about all this performance based design.  It has been some time since
I have reviewed it.  I understand it may make it's way into the 2000 code.  Not
sure about that though.

When I did look at it last, it didn't seem that the Owner could just set the
design standard.  There were many factors one could use to determine the design
standard.  A low use agricultural building may not be held to the same standard
as an office building.  The residential housing standard would be different from
the hospital standard.  The level of performance that would be allowed was more a
function of the type and use of the building than the Owners desires.

Maybe someone who knows ore about this could fill us in.

Lynn



Roger Turk wrote:
The only truly "performance based" design that I am aware of is that

> practiced by the aircraft industry in which an analytical analysis and design
> is made and a prototype built and tested to destruction.  If the tests do not
> produce the desired results, the design is modified, another prototype built
> and tested, etc., until the desired results are obtained.
>
> As I understand the proposed, "performance based design" concept, it will be
> up to the owner to determine the degree of protection/capacity that is to be
> incorporated into his/her design.  While I believe that a man's (or woman's)
> home is his/her castle, I cannot accept that an owner can determine the
> strength of his/her home should be, unless, the owner agrees that no one
> other than adult, competent members of the owner's family be permitted to
> enter the house and that the owner agrees to tear down the house when he/she
> moves out.
>
> Building codes have progressed based on what hasn't worked.  To go to a
> "performance based design" scheme would be to regress 100 years, throwing out
> all that has been learned in the past.
>
> If an owner is permitted to set his/her own design criteria, what need is
> there for building departments?  Every plan could be designed to a different
> criteria.
>
> Some buzz words sound good, but never really say what they mean.
>
> A. Roger Turk, P.E.(Structural)
> Tucson, Arizona