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Re: Code Created Malpractice Opportunity-Rigid v. Flexible Diaphragms

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<HTML><FONT  SIZE=3 PTSIZE=10>Dear Colleagues,<BR>
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I am not sure whether you saw and read Charles Greenlaw's reply, posted on the SEAOSC Listservice on May 30, 1999.  Like so many of his postings, I believe, it is worth your disk space and time to read this posting.<BR>
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He pays me too much "honor", but I must admit I do agree with his wording:..."I gather he might was well have mailed his comments directly to the dead-letter office."<BR>
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Perhaps these letters containing my comments would have been opened if they had not been "smoking" when they arrived.<BR>
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I will soon be posting another message to the SEAOSC Listservice concerning some very interesting and professional discussions I have had and continue to have with one of the authors of  FEMA 273 about the FEMA 273 inadequacies on how it addresses the problem of "Overturning",  FEMA 273, Section 2.11.4, page 2-37, and other problems with FEMA 273.  Apparently, this author is not afraid to open and respond to "smoking" letters.<BR>
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These concerns about how FEMA 273 addresses overturning were further refined from my earlier 1997 concerns, when I prepared my own seven pages of structural calculations,  dated October 27, 1998, based on a prototype building in a 1997 BSSC Report, "Validation of the Design and Analysis Procedures and Criteria."   I sent copies of the results of these calculations to over fifty structural engineers familiar with FEMA 273.  Only two of these fifty structural engineers took the time and effort to send me their comments, which were basically confirming what I had calculated and there were problems with the FEMA 273 provisions for overturning.<BR>
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The current wording in the ASCE/FEMA 273, April 12, 1999 Draft, concerning FEMA 273, Section 2.11.4 is basically the same (except for some increases in the values of the sidebar equation of Rot from 6 to 8 for Life Safety and Rot from 7.5 to 10 for Collapse Prevention) as the December 1997, FEMA 273, Section 2.11.4 wording.<BR>
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In my opinion, based on my work as a "peer reviewer" for three case study buildings in the BSSC Case Studies Project, which were prepared by  very competent structural engineering firms with considerable experience in the seismic evaluation and retrofit of buildings, the April 12, 1999 Draft, ASCE/FEMA 273, wording concerning Section 2.11.4 is inadequate and not complete.<BR>
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I realize that I am beginning to sound like a "broken record", but engineers are being educated about FEMA 273 at the ATC/ BSSC Regional Training Seminars and will attempt to apply FEMA 273 to "real" buildings.  I suspect that they will be finding significant problems with the capacities of these buildings to resist overturning and prescribe very expensive rehabilitation (retrofit) solutions to solve these overturning problems.  As one structural engineer in Southern California, who is recognized for his knowledge and background in the SEAOC Blue Book Provisions,  told me.."Even worse, inexperience engineers will conclude and tell their clients that it is almost impossible to prepare a rational and economically viable rehabilitation program for the client's buildings because of the excessive overturning requirements in FEMA 273, and ASCE/FEMA 273."  <BR>
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Such a conclusion will lead clients NOT to rehabilitation their buildings and is counter to FEMA's long term goals to mitigate the seismic problems in the United States.<BR>
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Frank E. McClure     FEMCCLURE(--nospam--at)aol.com   May 31,1999<BR>
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File:charlesgreenlaw5.doc <BR>
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