9. T.Chhay NPIC
Edl ∑ Pu nig V CabnÞúkbBaÄrsrub nigkMlaMgkat; erogKña ehIy Δ PaBdabeFobdWeRkTImYy first-
us o
order relative deflection rvagkMBUl nig)atrbs;Can;EdlbNþalmkBI V . RbEvg l CaRbEvgrbs;Ggát;rg
us c
karsgát;enAkñúgeRKagbgÁúM edayvas;BIGkS½eTAGkS½rbs;tMNrenAkñúgeRKag.
CaTUeTA Ggát;rgkarsgát;GacrgnUgPaBdabTTwg lateral deflection EdlbNþalmkBIm:Um:g;TIBIr
secondary moment. RbsinebIm:Um:g;TIBIr M ' RtUv)anbEnßmeTAelIm:Um:g;EdlGnuvtþelIssr M enaHm:Um:g;cug
a
eRkayKW M = M + M ' . viFIRbEhl approximate method sMrab;kMNt;m:Um:g;cugeRkay M KWCakarKuNm:U
a
m:g; M edayemKuNEdleKehAfa emKuNbEnßmm:Um:g; (magnifying moment factor) ehIyemKuNenHRtUvEt
a
FMCagb¤esμInwg 1.0 . b¤ M = δM nig δ ≥ 1.0 . m:Um:g; M RtUv)anTTYlBIkarviPaKeRKageGLasÞiceday
max a a
eRbIbnÞúkemKuN ehIyvaCam:Um:g;GtibrmaEdlmanGMeBIenAcugssr b¤enAkñúgssr RbsinebIbnÞúkxagmanvtþman.
RbsinebIT§iBl P − Δ RtUv)anykmkBicarNa vanwgcaM)ac;RtUvEteRbIkarviPaKdWeRkTIBIr edIm,IKitBI
TMnak;TMng nonlinear relationship rvagbnÞúk PaBdabTTwg nigm:Um:g;. eKGaceRbIkmμviFIkMuBüÚTr½edIm,IedaHRsay
va. bTdæan ACI Code GnuBaØatieGayeRbIkarviPaKssrdWeRkTImYy b¤dWeRkTIBIr. karviPaKssrdWeRkTIBIr
RtUv)antMrUveGayeRbIenAeBlEdl Klu / r > 100 . viFIKNnam:Um:g;bEnßmrbs; ACI Code CaviFIsMrYlsMrab;
KNnaemKuNbnÞúkbEnßmTaMgeRKagBRgwg nigeRKagminBRgwg.
6>2> m:Um:g;bEnßmenAkñúgeRKagGt;eyal Magnified Moments in Nonsway Frames
T§iBlrbs;pleFobrlas; slenderness ratio Klu / r enAkñúgGgát;rgkarsgát;éneRKagBRgwgGac
RtUv)anecalRbsinebI Klu / r ≤ 34 − 12M1 / M 2 dUcbgðajenAkñúgEpñk 5>1 . RbsinebI
Klu / r > 34 − 12 M1 / M 2 enaHT§iBlPaBrlas;RtUv)anBicarNa. dMeNIrkarkMNt;emKuNbEnßm δ ns enAkñúg
eRKagmineyalGacRtUv)ansegçbdUcxageRkam (ACI Code, section 10.12)³
1> kNt;faeRKagCaeRKagBRgwgTb;nwg sidesway b¤Gt; rYckMNt;RbEvgKμanTMr lu nigemKuNRbEvg
RbsiT§PaB K ¬ K RtUv)ansnμt;eGayesμI 1.0 ¦
2> KNnaPaBrwgRkajrbs;Ggát; EI edayeRbIsmIkar
0.2 Ec I g + Es I se
EI = (-12)
1 + βd
b¤smIkarEdlsMrYlCag
0.4 Ec I g
EI = (-13)
1 + βd
EI = 0.25Ec I g ¬sMrab; β d = 0.6 ¦ (-14)
Edl Ec = 4780 f 'c
Es = 2.1 ⋅105 MPa
ssrEvg 263
11. T.Chhay NPIC
T§iBlrbs;PaBrlas;GacRtUv)anecalenAkúñgeRKageyal sway frame ¬KμanBRgwg unbraced¦
enAeBlEdl Klu / r < 22 . karKNnaemKuNbEnßm magnification factored δ s sMrab;eRKageyal ¬Kμan
BRgwg¦ RtUv)ansegçbdUcxageRkam (ACI Code, Section 10.13)³
1> kMNt;faeRKagCaeRKagKμanBRgwgTb;nwg sidesway b¤Gt; rYckMNt;RbEvgKμanTMr lu nigemKuN
RbEvgRbsiT§PaB K EdlGacTTYlBIsmIkar (-4) (-5) nig (-6) b¤düaRkamrUbTI3.
2-4> KNna EI / Pc nig Cm dUceGaykñúgsmIkar (-12) dl; (-16). cMNaMfa βd ¬edIm,IKNna EI ¦KW
CapleFobrvagkMlaMgkat;TTwgefremKuNGtibrma maximum factored sustained shear
tamCan; nigkMlaMgkat;TTwgemKuNsrubenAkñúgCan;enaH.
5> KNnaemKuNm:Um:g;bEnßm moment-magnifier factor/ δ s ³
1
δs = ≥ 1.0 (-19)
1 − (∑ Pu / 0.75∑ Pc )
Edl δ s ≤ 2.5 nig ∑ Pu CaplbUkbnÞúkbBaÄrTaMgGs;enAkñúgmYyCan; nig ∑ Pc CaplbUk
bnÞúksMrab;ssrEdlTb;nwgkareyal sway enAkñúgmYyCan;. dUcKña³
M 2s
δsM s = ≥ Ms (-20)
1 − (∑ Pu / 0.75∑ Pc )
Edl M s Cam:Um:g;emKuNxagcugbNþalmkBIbnÞúkEdlbegáItkareyalEdlTTYlyk)an.
6> KNnam:Um:g;cugbEnßm M1 nig M 2 enAxagcugGgát;rgkarsgát;EtÉg dUcxageRkam³
M1 = M1ns + δ s M1s (-21)
M 2 = M 2ns + δ s M 2 s (-22)
Edl M1ns nig M 2ns Cam:Um:g;EdlTTYlBIlkçxNÐGt;eyal b:uEnþ M1s nig M 2s Cam:Um:g;Edl
TTYl)anBIlkçxNÐeyal. RbsinebI M 2 > M1 BIkarviPaKeRKag enaHkarKNnam:Um:g;bEnßmKW³
M c = M 2ns + δ s M 2 s (-23)
m:Um:g;cug M1 nig M 2 enAkñúgsmIkar (-21) (-22) nig (-23) manm:Um:g;Gt;eyal bUknigm:Um:g;
eyalbEnßm CamYynwglkçxNÐEdl
lu 35
< (-24)
r Pu / f 'c Ag
enAkñúgkrNIenH Ggát;rgkarsgát;KYrEtRtUv)anKNnasMrab;bnÞúkemKuNtamGkS½ Pu nig M c .
b:uEnþkñúgkrNIEdl
lu 35
> (-25)
r Pu / f 'c Ag
Ggát;rgkarsgát;KYrEtRtUv)anKNnasMrab; Pu nigm:Um:g;Gt;eyalbEnßm δ ns M 2 bUkCamYy
nwgm:Um:g;eyalbEnßm δ s M 2 CamYynwgm:Um:g;KNna M c = δ ns M 2ns + δ s M 2s . krNIenHGac
ssrEvg 265