HomeMy WebLinkAbout0521.094City of Palo Alto
"" ___ C!ty_ Man ~ger' s_Re(l~!::!
HONORABLE CTlY COUNCIL
VEPMtTMEN1': Pl.~ning and
Community £rniroDlIW!Dt
AGENU" DATE: _\>or ZS, l~
Sl1BJEcr: EmorttD<) Onji,u"l<-e 10 AmHd tt.. 1991 Unirorm 8uilding Code (UBe)
Rt'fJlting to Sr~1 Special ~fontflJt·R€'5istiJ1g Frame {SMRF) Buildings.
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Ack'pt tMe attached C'mer~el1C:, ,qdirl,,"r;~'e and 'injin.~" (kklin~ llBC SC'7tion 271O{g)l.B :md
re\.j~ing ~.:'tion 211Ce;g)1.C,
Rn:Q:'l~l~~IiO"S
C;.'uncil i;,:o'Opt th.;: err.~rbr!h)· o~Jin;,;.n('e and firJ.jir.g~.
POI.IO' IMP! ICUlQ1'S
This act.ion does !1C'11 repfeY:!ll an:.' {:~nge !o n~sting p(i!icie.~.
f.~_ClnWE Srw,!..\ID'
o.'er 110 building, v,1th welded steel moment fr.:tmes. (d~.;t;:ription attached) suffered
unexpected, and often ex:en5I\'(", fracn.LIe~ in or near girder-to-colunm weld ... during the
Northridge Earthquake of JauuaI)' i7. 1994,
Steel 'l\clded moment frames are intended 10 undergo significant inelastic action whUe
maintaining ~tungt..b and ductility in regions of modt:(dle to high seismicity. However,
observatiom from 1M Nonhridge E.arthquake, and liU'oseqlJtnl te-su, at the University of Texas
at Austin, indi.:ate that the rormectio. delai! pr..rnbeC by UBC Section 2710(g)l.B doc. not
reliably assure tbat strecglh and ductility <= be sustained without the observed fracturing.
Ba<;ed 00 ttK-('\rjdence 5ubrr-Jtted :and support from the Structural Engineers rusociation of
California (SS'\OC). the State's Seismic Safety Commis!'ion petitioned tht Imt:rnational
Conference of Building Officials (ICBO) to dele!e UBC Sectinn 271O(g)l.B '" an emergency
code change. The Board of Director.; of ICBO concurred and deleted the section on
September 14, 1994.
On October 24, 1994. Inc: C-aliforr:.i.2:, Building Standards. Commis.s.ion (CBSC) adopted a similar
change 10 the California Bu,lding Code (Bulletin 94"02 altached) that applies to Stale regulated
and owned buiJdings.. Howe'w"cr, Lhe eBSe does. not have the authority to regulate buildings
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at the local government ltv-e!. The Sei5m:i<: Safety Commission has. ,;!ror.gl; urged local
guvernmt'Dts to incorporate these code chsnge5 .2.:! e~rgcn(')" actiQns
By tat-inj: thi. .. action, the City wHl still all"",,' steel moment frames to be C\.1[lStructed bul wiD
require them to meet more corc.ervatNe connection design standards and impI'O"Y'eC welding
t..obniques, .. recommended by SEAOC. If tllis action is :101 uken. staff dDe1 not have tbe
aulnority to deny. building permit .wlicarion WI m«ts <be current rode. The potential fOf
baving w issue permits for structures incorporatiD.,i: these problems is the basis fOT the
recommendation that the attached Qrdinance be adopted as. an urge-rery mailer ~ffu"·Jl.'e
immediately, upon Council actlon
There are no penllh applicati0n; in the plan re\i~_w offt..:e tr3.t ~(I.i!\i "f.;'C aH.:"('teJ by the
ordinance at L,'Ii.<. time, One kJl{n .. n S:\~RF bili1dlfl£ j, cuncntly inil-'~f (~~_;!,;n, ~r.d ~hc ~~TlJcturjl
engineer is fuH), a)l.'aTe of th;~ code amendmenl<
EIS£:ilL..JMP AeI
There is no fiscal impact.
ENVIRONMENT At.ASSESS ~lEJ'cr
Emergency adoption of an ordinance is e,l.'empl from CEQA< En\ironmen1:.-..1 J.S.5.!':>.s.men( L'i. mn
required,
rnACHME...I'IT.S
Steel ~~cment Frame ~s.cription
CBse Bulletin 94-02
Ordinance
Finding
PREPARED BY: Fred Hennan
DEPARTMENT HEAD REVIEW:
CITY Mfu"AGER AfPROV A[~ ~ "-.IL'" t!. jy.. ~Jl BRNARD M. SrRoJiW1lf' '
Assistant Cit)' :\hnager
CMR:S.II:94 ..... ' '"
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,~Stm MofIuntFrtmoa?
~, it'; ""'; ,~ba!lolhlpandmanymid, al1,,, .. _loaIIdlopniyoo __ ttam.sto
..... , l' fI •• Sfromwindsorearthquaka.
l-.iI _ ..... 'a bafiding ...-I>y 'wiru! are
_ ...... Iy, "I'J'IIedoad <MY "'-Cam>oroeiy. ' ___ ~-frominlomol
___ deftIop .. thegoand. and !here-
~ .. baiIdirw'. ' I.,.... -Ie This.is
...... _ e.foroethat&J '8ti sIandiDg OIl. bus
8eI5 when the bF» • J aI&. In the CMe of. build-
lag. _ boeo ... primarily .. !he 1Ioc<_.
""-the .,.;ghts .... cn ..... b.1Ed.
_ momenl _ consist of beamo md rol-
UQUlS joined by a combination of weldin!! and b-,lt
, lng, They ""'"' Ial=I Jcods tluwgh bondnlg of u., mme eJanmll; .. _ in the top 4=, lnthe
OM< of ... !nc! Ioods and mOOera" earthq-...J=, steel
-~~ nsing~ OrrI'P"t htt11dmg..code.sno
intended to rema.i:n el&stic. 10. Q+tm words. whc-n trte
lo:ld.ing ceases, an oj the ~ ~ and columns
constituti:ng the b-ame are e-:pecred tQ retum to fuei:r
original positioon without any permantYI! deformation.
This ~ not the case for a major earthqu.tke, J-.ow.
ever, During strong ground """"'" the steel man
hers ~ expected to bd\a.~ in a ductile trW'I!"IeT:
~ and .-mg """'SY, Alto< the tanh
qual::e,· permanent defunnati..:m of ihe sl.trel-·frame
memberslsexp<dEd, s.v.nl Bp<cial detailing P"""
sions in the CtD"f'f!llt code are intended to elS'.U'e
ductile perfonnanc2: however, as ""1'1amed m the
accompanying a.1:'tkle, this perlonr.a.nc€ was not
achieved during the N~ Earthq ..... ,
The boI1om figu<e klentillos the vari<>w <X>Ollj>O'
:nerU:s of a typic:aI moment connection. Thes.e or simi
lar coonectioN are used to join all ilf a moII'If!nt
£ra.me'fj .memben.. In aD moment connections, the
beam e.ng.. are weld<d du.ctly to the column.
thereby providing bendir.g resishu\,", lleam webs
a.re usw.lly bolted to (he oolumn using shear C'Uru1eC
"'-' plata It s/KNld be noted that, n01"JlWly, and
espedaDy in more .recent ronst:ruction.. few of a
bun.d.ing's beams and columns are used as c0mpo
nents of moment _ Corn!equmtly, moot of !he
steel framing is joined only by simple bolted
connections and does not contributE to the !a2al
ioad. resistance.
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~"'I'f Of ~-sT .... n: .. NO ~ S8MCE'$ AGfNCT
CAUFORNIA WILDING STANDARDS COMMISSION
.c.ll J $l1I&T, $I.1I1'1i ~
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INFORMATION BULLETIN NO. S4-02
November 1, 1994
The Calilomia Building Standards ~mmission (CSSe) adopted and approved, on an
emergency basis, modifications to building standards regulating special moment·
resisting frames. The emergency standards were jointly proposed by the Division of
the Stale Architect (DSA), the Office 01 S!alewide Health Planning and Development
(OSHPD). aod Ihe Commission in response to the Nonhridge Earthquake in January 01
this yeai, The standards reierenced a srmHar action t~Ken by the lntemational
Conlerenee 01 Building Officials (ICBO) ai its annual meeting in September 19r4, which
mooilied lhe 1994 edition 01 the Uniform Building Code (UBC)[s". attaChed). The
action by the csse aHeeled the 1991 edition 01 the USC as relerenced in the 1992
CaJ'itomla BUilding Cooe.
As proposed by both DSA and OSHPD, Ihe emergency regulations repealed California
8~lldlng Code (Calilorr,;a Code 01 R~ulatlons, Tiile 24, Pa~ 2), State Chapter 27,
,Section 2710(9)1 B and amended Section 27101g)IC, .... ,th application for public
'-elementary and secondarj schools, community college bl!ildings, state~owned or state·
ieased essential services buiid/ngs, general acute 4 car8 hospitals, acute p.c:;ychiatric
hospitals, clinics, and skilled· nursing faG'lilies. As adopted oy tne CommiSSion, the
emergency action repealed Caillornia Building Code, Chapter 27, Section 2710(g)1 B
ano amended Seelion 2710(g)1C, with application for slate buildings IIncludlng
buildings constructed by the Truslees 01 Ihe C"clomia SIale Univers~ies anti C\llieges
and the Aeg<lnts 01 the University of Calilomia). The emergency standards do not
apjl!y at the Iocel government level.
Tha Commission's action was limited to application to Ihe state programs described
aixNe. Local government may consider taking action similar to the Commission's in
amending me t991 Calilornla Building Code In compliance with Section 17958.7 01 the
Health and Safety Code for local construction.
The Commission filed the emergenoy standards on October 25, 1994 with the Secretary
01 State, al which time they became effective and enlorceabi •. The standardS are being
codified and will be sent to the ICBO for immediate publicalion as an Emergency
Supplement 10 the California Building Coo •.
Attachment
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R.,.... _600 0( _ 1110(11) 1I! as follows:
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L'RllJi' t.nl_ "I ,Wt. ," eli 'ia:C'ile"'_!Ile.:lt:WJc 'uHe.,.,es,,"'· "mof
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.11'. f.'" "ei ...... ppa iI) .... ,..3fR;.Jt;) ... l.epJ "'r~IlIIiRg&efftMe,.esaw'"
uiau::i:uf _ 'AAleeliuA aJ.Jtllllltailhoe,sd&lIW:S!$i=I".._.?Gp cutt6tUt.S~_"'II!l!:M:ef
._ (i.-.~~,) fwJ ,_ I:i! 1 me, 'at lRed:e ~ ~e:; .!:£ i!I arhis, 51fe1l£l:l'ihlJiftg.
F8f .... Silllll ...... ! h:oeesr' ... ialhe, •• .,'aI!e e •• ugi. .... 'I1eeMeelltft ee n :b6Pl5M:ltbeAl:fU~e'e)L1e.~
af I'd", •• ne ~eul. ew ... eutt! •• _s I!Ie ~ ee'\tft11'1. 'Fb:1t e14iAg s)Ja,\j As,e & 51Rflgt.\ eftJ!alsle el
!Ie • " ; !II ;ee-X ~e::.t'l efth& Ae·lft:1 '"' lltl er~ t;'ab ~e.?e gUEef !l~!if sl=te21teM:"'xg5) IfII(!<l:l~ af
,;ilieAIII eti'; _ .• firi~i:iI3ll.I:',.e ~~ hi~ Jt ... f\~!. ~ell:l 9f htl!
~~~~:;>;""""!..il!~ li·~2C;;\..;'& m~,ru, CO".fi-::\:WC;l cOHfiS\Wol!iOns miJizlng weld.s Of high-strength bollS
r-e. ~ cl"h. .g' .""" ." te ~t''' :6! 11,;, J .. ~.~~: d5(; j 'r Hoe; -"! W ~~ Sh,ail d(m~ruirale .. b't' ~p[Jmyed cycltc leSt
~ 0/ uJ':",:l.a!.i';).., In.~ .lJ}11~l' :0 :rusta.jn intJastic Nation {md !£' m:~l "1Ie. dtv~loo We strength ol'.tri.o ltl pa.ragrapb
,4. s..'-...:n't ~riaJ :!H~ ~rrt(1 of Srn QW!"'JtffIlgth and grain hardrning. 1'~1!!'~ fsn.'eRi'.SI.:e k; she.1\ ")
OI6oleule!::'! . l~~!!O fill of !!he "': 4(!:lc ~f Ihe eetuteelil:!l ell litil~ sh6l:l 1M) "be lli5~a
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OlWINAl,.CE NO"
ORDIXANCE OF THE OJUNCIL OF THE CIT'"( OF PALO ALTO
AMBIIDING 'mB 1991 IIDITION OF THE ONlPORM BUILDlNG
CODE; A.lIotENDrNG C'P..A.P'TRR 16.04 OF THE PALO ALT'O
MUNICIPAL CODB; AND DECIARING AN E:MRRGENCY
'NHER.BAS, over 110 buildiIJg8 with welded steel moment fra:r.es
suffered unexpected, and often exteru!ive, fractures in or near
9irde~-to-column weld..'i during the Northridge Eartl".quak.e of
January 17, 1~94; and
WHEREAS, sceel
significant inelastic
ductility iro req:i.orls
",elde:j ~-'2.~€'r.t fra.!:".es are intended to undergo
ilct:,::"n \or'hj_le ,.=intainin3 st.ren:;lth and
Ol' l':'".2,,jerat-e ~'J l~i']h seis:::-:icity; bOio{ever,
obge! ....... rations (ru[ii the !;erth["i~g·~ 21.l',':r,'l:\'3:':e ar.c :s'.::CseqLlent tests Cit
the Univer-sit)' -of Tex,a;t at ;'.U!'lti.'J i;-"jic.:>t.(: tbat t'r,~ cormect.ion
detail c1.11"rently p~l~sc.:ibsj t,y tho"-l1rlif0.r!':", ;:~i.).dir.:~ C.'r.:.-:)e (i..'E::) does
not .reliably dsr:;,l:le :-ho.t ;:.~:::r,~r,grh "'_rl'j JI",c~.iliq' L.:,~n 'c~ susc:.ain.ad
'Witr,out the obs~l"' .. C:"::i fr3.cl;:urir,:3; and
WHEREAS, baaej on th(~ evi.dE-rlce B1Jt~tted and 5'.!PPQrt fl:-om
the Structural EngineerE; Associar io~ of California (SEAOCi, the
State's S-eiSIr.ic Safet.y COOL.1.isr;ial) petition",d th~ lntern.::!tional
Conference of Building Off icialS: 1 IeBO) to <ic:1H.,:, lJBC S~ction ,2'710
(g) 1.B and t.o amend i.J't!C St:?C'tio~ 2'}lO (9) 1 C as e!!',ergency code
ante:ndl'l1ents, to substitute l7'tOre conservative connection desigil
9tandar-ds and improve-j Ifoteldiug techniq-I.les; lind
WHEREAS, The Beard of Directors of lCBO concurl:ed wit.h the
Seismic Safety Commission and ~de the amendments to the USC on
September ~4, 1994; and
HHRRBAS. On October 201, 1994, the California Building
Standards Cat'l!Uasion {CBSe) adapted a similar change to the
California E1.!ildin-g Code, " .. hich applies to State regulated aIld
cwned buildings, but does not apply to regula~ion of buildings at
'the local level; and
WHBREAS, the City Council believes r.hat such amendments
should .be :made to the building regul,:.,ticns of the Palo Altc
Municipal Code to ensur-e th;· [Lost seisl7LiceJ'lJy-safe constl:uction
p:JBsible for local safety; and
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9041111*'0031054
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WHERBAS~ the Council believes that the need for these
changes: is urgent and adoption of the amendmentB is nece~sary as aD
emergency measure for preae1ving the pu.blic peace, health or
Batety, becauf!Je of the need to prevent further huilding-a trcrn being
constructed under the cur~ently perw~tted etandards. Unless and
until these changes are made the.l-e is nothing to pr~vent buildings
fram being constructed in t-he City of Palo Alto io a manner tr.at is
now understood to be potentially dange~ou8.
NOW j THEREFORE, the Council of the City of palo Alto dc-ee
ORDAIN as follows:
SHerrON 1. Section 16.04.145 is heJ:eby a,:l.de<l to Ti:.:l~ 16
[Building Reg\llationsl of tt'~e Palo Alto ~icipal ('we t.O read, aE!
follows:
16.04.145
1. B of the Unifonr, Build.ing C'-ode is delet eo.
~I.Ql:L.2...... Section :;'6.04.146 is he:::ebi' add€,j, to Y:tle H
(Building Reg-l.llar..ionsJ of the Palo A1 to l11micip-=.1 Coje: to read d:5
follows:
U.0 •• 146 Seetion 2?l0 (9') Le ~d,",. Section 2710 (9)
l.C of the UniforI!1. BLI.ilding Code is a.'TI.::nded to ~'?ad:
Section 2710 (9) l.C. Conn~ction strength. Connect-ion
configurations utilizing welds or-r.igh-strength bolts shall
demonstrate, by approved cyclic test results C~ calculation, the
abi~ity to &\1stain inelaat.ic rot.ation and develop the 8treng'th
criteria in paragraph A above. conSidering the effect of st,e.el
cverstrength and strain hardening.
SECTION 3. Pursuant to Section 17958.? of the California
Health and Safet:.y Code, the Council adopts the following finding as
support for this local ameodment to the UBC:
Finding: The deletion of UBC Section 2710 (g)
~.B and the amendment to UBC Section 2?10 (9)
1.C are necessary due to Palo Alto's proximity
to known active seismic faults, a geologic
condition.
SECTION 4.
prcject~ and is
The Council finds that this is an emergency
therefore exempt from the provisions of the
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california Environmenta2 Quality Act (CEQA) , pursuant to section
15269 of the CEQA guidelines.
SECTION 4. Based on the reaEions set. forth above, the
council declares that the code amendments adopted herein are
nace8sary as an emergency measure to protect the public peace,
health and Bafety, and shall be effective immediat~ly upon their
adoption.
This ordinance was passed. at a 7:egular meeting of the
council of the City of Palo Alto on Nov~b~r 2S, 1994, on a four
fifths vote of all COUDcil Members present at the meeting as
follows:
INTRODUCED AND PASSED:
AYES:
NOES:
ABSBNT:
ABSTllNl'IONS:
ATl'BST:
City Clerk
APPROVED AS TO PORM:
senior ABst. City At.torn,,=,~~
Mlll'.OO1l0::S4
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APPROVED:
._----_.--_ .. -Hayer
City Manager
Director of Finance
Director of Planning and
Community Environment
Chief Transportation Official
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flNDING
Section 17958.7 of the Health an<l Safety C.ode requires the governing body of the City to make
an ...... finding thai modification 10 a model code is reasonably necessary due to local
dimatic, geologic or topographical conditions.
F"mdiDg: ~ del.tion of Section 2710(g)1.B and modification to Section 2710(g)I.C is
necessary due to Palo Alto'. pro.rimity to known active seismic faults, a geologic condition.
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