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"And The Buildings Will Not Even Catch a Cold."-Performance Based Seismic Design

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The following "Letter to the Editor" was published in 1996 Structural 
Engineers Association of Northern California and Southern California 
newsletters.  In response to numerous requests, it is repeated here so others 
who do not have access to these newsletters will have the opportunity to read 
this "Letter to the Editor", entitled "And the Buildings Will Not Even Catch 
a Cold." 

With the continuing emphasis on "Performance Based Seismic Design" as 
expressed in the Pacific Earthquake Engineering Research Center, Vol. 2, No. 
1, January 1999, PEER CENTER NEWS, web site:, and 
other similar seismic engineering bulletins and newsletters, as well as FEMA 
273 and 310 Guidelines, it is timely to present again the following "Letter 
to the Editor."


"On a recent airplane flight in early December 1995, I had the privilege of 
talking to a professor from one of the California Universities for Research 
in Earthquake Engineering (CUREe) universities.  He expressed his concerns 
about the ethical and professional liability issues related to the structural 
engineering profession being able to met the goals of  Vision 2000, which is 
to develop the framework for procedures that yield structures of predictable 
seismic performance - Performance Based Seismic Design.

"He was very concerned about the ability of knowledgeable structural 
engineers to design and retrofit building to meet the Vision 2000 performance 
goals and levels of  "Fully Operational" and "Operational" (Refer to Figure 
2-1: Spectrum of Damage States, Vision 2000 - Part 1, April 3, 1995.)  His 
concerns was that structural engineers have an inadequate data base of full 
size testing of systems and components and their actual earthquake 
performance on which to base the necessary engineering judgments to design 
and retrofit buildings to meet these seismic performance goals and objectives.

He was also concerned about the apparent structural engineer's innocence and 
unsophisticated understanding of the legal issues related to their practice 
compared to medical doctors.  All medical doctors eventually "fail" and lose 
all their patients through death if they outlive their patients.  They do not 
even try to offer perpetual life unless they are quacks or charlatans.  Yet 
they are will to spend considerable sums of your money - with your 
permission, of course - to extend your life a few years.  If you follow their 
recommendations your life can be extended.  However, they do not offer 
perpetual life and along the way you will still catch colds.

"Now with Vision 2000 performance levels of  "Fully Operational" and 
Operational" structural engineers are offering to provide owners with the 
equivalent of "implied warranties" and seismic risk-free "perpetual life" for 
their buildings if these structural engineers will just follow some enhanced 
design and quality assurance procedures.


Frank E. McClure, Consulting Structural Engineer
* All rights reserved.  July 30, 1996. 

Note: The FEMA 273 Guidelines Performance Level of "Immediate Occupancy" is 
equivalent to SEAOC Vision 2000 Rating of  "Fully Operational", and FEMA 273 
Guidelines Performance Level of  "Damage Control" is equivalent to SEAOC 
Vision 2000 Rating of "Operational."  (Reference: Chris Poland, PEER CENTER 
NEWS, Vol. 2, No. 1, January 1999.)