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Re: California Building Code seismic provisions.[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: seaint(--nospam--at)seaint.org, FEMCCLURE(--nospam--at)aol.com
- Subject: Re: California Building Code seismic provisions.
- From: Charles Greenlaw <cgreenlaw(--nospam--at)speedlink.com>
- Date: Mon, 27 Dec 1999 23:27:37 -0800
Frank McClure, your recognition of an impending watering down of seismic standards in the Sacramento area, in the name of uniformity or consistency, and your call to action to restore a higher standard by an extraordinary means, has a very curious and successful precedent. But the roles of perpetrator and rescuer were very, very different the previous time. Very different, indeed. But first: Frank, you wrote: >Martin Johnson, >Your example of permitting essentially unreinforced masonry construction to >be used in the Sacramento area of one of the important problems with the 2000 >IBC. I am encouraged that you and the SEAOC Seismology and Code Committees >are actively involved in the 2000 IBC and 2001 IBC Supplement code changes >process. Your example of the permitting unreinforced masonry construction in >certain areas of California, based on the IBC mapping, would be but one >example of future California Building Code amendments to correct the 2000 IBC >before the 2000 IBC is adopted in California. > >Your comments concerning FEMA's serious desire to establish a "uniform >national standard" are very important.... ------------------------------------------ So what happened last time? It was the 1981-88 Blue Book Rewrite by SEAOC Seismology Committee, and the push was to incorporate the results and format of the monumental, govt-funded, 1978 ATC-3 document. SEAOC Seismology had a small Zonation Subcommittee that was enamored of ATC-3's seismic zoning maps for the whole U.S., and which were based on the works of Algermissen and Perkins. The Zonation Subcommittee proposed seismic zone 2 as including all of the Sacramento and northern San Joaquin Valleys and the whole northeast quadrant of California. (The break between rigorous vs lax detailing and ductility requirements occurred at the zone 3--zone 2 boundary; the then-existing Blue Book and UBC had no zone 2 in California.) With little attention, the full Seismology Committee approved a somewhat scaled back extent of zone 2, such that it dipped south only to a point some miles north of Sacramento, but still included many fast growing cities in the northstate. Then the Central Section of SEAOC found out. Central's region included all of the newly voted territory that would drop to zone two. Central's Seismology Committee woke up unhappy, and Central's general membership and Board of Directors was VERY unhappy. But what to do? The Zonation people were adamant that consistency was paramount and state line-based zones were not "rational". Central's delegates to SEAOC Seismology knew they could not prevail in another vote there. Ah, well....think: The SEAOC policy buck really doesn't stop at the Seismology Committee. Central's members on the SEAOC Board of Directors offered their local Board a chance to take the matter away from SEAOC Seismology, and the Central Board rose to the opportunity, and voted to go for it. Remember, the Central Section Board were the ONLY persons involved who were directly voted into office by the general membership of Central Section. (Nobody on any Seismology Committee was voted thereto or into any committee position by any general membership election. Dennis Wish raised this point recently.) So Central's delegates at the next SEAOC Board Meeting moved and seconded a motion that we could then use our Bylaws-given veto power on, and that if vetoed would have the effect of nullifying Seismology's adoption of zone 2 wherever Central's Board members didn't want it. This move was regarded very dourly, and as sort of bad sportsmanship. The two Zonation subcommittee members showed up and argued their case. (One is now a Fellow member of Northern; the other is currently a SEAOC Board member from Southern.) Central argued that ATC-3 itself said that "acceptable seismic risk is a matter of public policy determined by a specific government body", and that local bodies in the subject territory had no better policy advice than the UBC, that (at the time) came straight from our Blue Book. We felt that zone 2 was an abdication of due concern for public expectations in Central's territory for good seismic performance. There wasn't much joy in Mudville, but zone 2 was struck out. The UBC kept it out ever since. And Oregon, then zone 2 just across the state line, now has gone to zones 3 and 4 where SEAOC Seismology in 1986 insisted on zone 2! For an epilogue, it might be noted that Seismology Committee carried on uncowed and grew ever more dominant in SEAOC affairs, while local SEAOC Sections and their elected Board delegates have been relegated to the backwater. The SEAOC Bylaws have been amended in the last year, without general membership vote, so that no one Section's delegates can obstruct any action of the state SEAOC Board, or of the Seismology Committee. The way zone 2 was kept out last time is no longer available, compliments of the several boards of directors themselves, acting in the name of "increased efficiency". Well, happy efficiency, everyone. Here comes zone two (or its equivalent) all over again. Good Luck to Seismology Committee at the Building Standards Commission, and have ready a good argument against uniformity and consistency. Charles O. Greenlaw, SE Sacramento CA
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