បេតុងពង្រឹងដោយដែក 15 xv-design-for-torsion

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm esckIepIm Introduction

    kugRtaMgrmYlekItmanenAkgmuxkat;FwmenAeBlEdlm:Um:g;manGMeBIRsbeTAnwgmuxkat;enaH.m:Um:g;rmYleFVIeGayGgt;vil nigmansameRbHenAelIprbs;va CaTUeTAEtgekItmanenAelImuxkat;mUl.edIm,IbgajkugRtaMgrmYl eKGnuvtkMlaMgrmYl T Fwm cantilever muxkat;mUlEdleFVIBIelastichomogenous materialdUcbgajkgrUbTI15>1. kMlaMgrmYlnwgeFVIeGayFwmvil. cMnuc B clteTA

    cMnuc 'B enAxagcugrbs;Fwm b:uEncugmageTotrbs;FwmRtUv)anbgb;. mMuRtUv)aneKehAfa mMurmYl(angle of twist). bg; OBAO' nwgdUrrageTACarag ''OBAO . edaysnt;fa Ggt;enArkSaRbEvgrbs;vadEdl enaH shear strainKW

    L

    r

    L

    BB ==

    '

    Edl L CaRbEvgrbs;Fwm nig rCakaMrbs;muxkat;rgVg;.

    enAkgeRKOgbgMebtugGarem:Ggt;nwgrgm:Um:g;rmYlenAeBlGgt;enaHekagenAkgbg;/ RTcantilever slab/ mannaTICa spandrel beam (end beam)/ bCaEpkrbs;CeNIrvil.

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 347

    Ggt;eRKOgbgMGacrgnUvEtkMlaMgrmYlsuTbenAkgkrNICaeRcIn vargCamYyKakgeBlEtmYynUvkMlaMgkat;TTwg nigm:Um:g;Bt;. ]TahrN_TI15>1 bgajBIkMlaMgepSgEdlGacGnuvtmkelImuxkat;

    epSgKanFwm cantilever.]TahrN_TI 5>

    KNnakMlaMgEdlmanGMeBIenAmuxkat;!/ @ nig # nFwm cantileverEdlbgajenAkgrUbTI 15>2. FwmrgnUvkMlaMgbBar kNP 671= / kMlaMgedk kNP 5.532 = EdleFVIGMeBIenAcMnuc Cnigbnkedk

    kNP 893= EdlGnuvtenAcMnuc B nigEkgeTAnwgTisedArbs;kMlaMg 2P .

    dMeNaHRsay

    yk =N kMlaMgEkg (normal force)/ =V kMlaMgkat;(shear force)/ =M m:Um:g;Bt;(bendingmoment)/ T=m:Um:g;rmYl (torsional moment). kMlaMgTaMgGs;RtUv)anbgajenAkgtaragxageRkammuxkat; )(kNN ).( mkNMx ).( mkNMy )(kNVx )(kNVy ).( mkNT

    ! 0 9.180 45.144 5.53 67 0 @ 5.53 sgt; 0 45.144 89 67 9.180 # 5.53 sgt; 2.241 85.464 89 67 9.180

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm m:Um:g;rmYlenAkgFwm Torsional Moments in Beams

    dUcbgajenAkgrUbTI15>1 kMlaMgGacGnuvtenAelIeRKagsMNg;GKar edayeFVIeGaymanm:Um:g;rmYl. RbsinebIkMlaMgcMcMnuc P GnuvtenARtg;cMnuc CenAelIeRKag ABCdUcbgajenAkgrUb 15>3 avabegItm:Um:g;rmYl PZT= enAkgFwm AB Rtg;cMnuc D. enAeBl D sitenAkNalElVgnFwm AB

    enaHm:Um:g;rmYlKNnaenAkgkMNat;AD esInwgm:Um:g;rmYlKNnaenAkgkMNat; DB besInwg T2

    1 . Rb

    sinebIkMral cantilever slabRtUv)anRTedayFwm AB rUbTI 15>3b enaHkMralxNbegItm:Um:g;rmYlBRgayesI tm tambeNayFwm AB . m:Um:g;rmYlBRgayesIenH KWekItBIbnkenAelIcMerokTTwkmYyktarbs;kMralxN. RbsinebI SCaTTwgn cantilever slabnig w CabnkenAelIkMralxN 2/mkN enaH 2/2wSmt= mmkN /. nFwm AB . m:Um:g;rmYlKNnaGtibrmaenAkgFwm AB KW

    2/LmT t= EdlGnuvtenARtg;cMnuc A nig B . krNIbnkepSgeTotRtUv)anbgajenAkgtarag15>1. CaTUeTA daRkamm:Um:g;rmYlenAkgFwmmanrag nigmantMldUcKanwgdaRkamkMlaMgkat;TTWgsM

    rab;FwmEdlrgnUvkMlaMg tm nig T.

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 349

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm kugRtaMgrmYl Torsional Moments in Beams

    edayBicarNaelIFwm cantileverEdlmanmuxkat;mUl rUbTI15>1 enAeBlEdlm:Um:g;rmYl T manGMeBIelIFwm vanwgbegIteGaymankMlaMgkat;TTwg dV EkgeTAnwgkaMrbs;muxkat;. BIlkxNl4 enaHGaMgtg;sIuetnkMlaMgrmYlKW

    = rdVT

    edayykv

    CakugRtaMgkMlaMgkat;TTWgenaHvdAdV= nig = rvdAT kMlaMgkat;TTwgeGLasicGtibrmaekItmanenApxageRkArbs;muxkat;rgVg;Rtg;kaM rCamYynwgkM

    ras;drenaHkMlaMgrmYlGacRtUv)ankMNt;edayKitm:Um:g;eFobnwgcMnuc 0 sMrab;RkLapkg

    ( )vrrdrdT 2= Edl rdr2 CaRkLapkg nigv CakugRtaMgkMlaMgkat;TTwgenAkgkg. dUcenH

    ( ) drrvrrdrTRR

    ==

    0

    2

    0

    22

    !%>!sMrab;muxkat;RbehagEdlmankaMxagkg 1R /drrT

    R

    R= 122 !%>@

    sMrab;muxkat;tan;edayeRbIsmIkar !%>! nig Rrvv /max=

    =

    =

    RRdrrv

    Rdr

    R

    rvrT

    0

    3max

    max

    0

    2 22

    3max

    4

    max

    24

    2Rv

    Rv

    R

    =

    =

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 351

    3max

    2

    R

    Tv

    = !%>#

    m:Um:g;niclPaBb:UElrnmuxkat;rgVg;KW 2/4RJ = . dUcenH kugRtaMgkMlaMgkat;GacRtUv)an

    sresrCaGnuKmn_nm:Um:g;niclPaBb:UElrdUcxageRkam

    J

    TRv =max !%>$

    4> m:Um:g;rmYlenAkgmuxkat;ctuekaN Torsional Moments in Rectangular Sections

    karKNnakugRtaMgenAkgGgt;manmuxkat;minmUlEdlrgbnkrmYlminsamBadUckarKNnasMrab;muxkat;mUleT. b:uEnlTplEdlTTYlBIRTwsIeGLasic (theory of elasticity)bgajfakugRtaMg

    kMlaMgkat;TTwgGtibrmasMrab;muxkat;ctuekaNEkgGacRtUv)ankMNt;dUcxageRkam

    yx

    Tv

    2max = !%>%

    Edl =T kMlaMgrmYlEdlGnuvt=x RCugxIrbs;muxkat;ctuekaN=y RCugEvgrbs;muxkat;ctuekaN=

    emKuNEdlGaRsynwgpleFobnxy /

    tMlrbs;vaRtUv)aneGayenAkgtaragxageRkam.

    xy / 0.1 2.1 5.1 0.2 0.4 10

    208.0 219.0 231.0 246.0 282.0 312.0 kugRtaMgkMlaMgkat;TTwgGtibrmaekItmanenAtamGkSnRCugEvg y rUbTI 15>5.sMrab;Ggt;EdlekItBIkarpMnmuxkat;ctuekaNEkg dUcCamuxkat;GkSr L / T nig I tMl

    GacRtUv)ansn

    t;faes

    Inwg 3/1 ehIymuxkat;GacRtUv)anEckecjCamuxkat;ctuekaNCaeRcInEdlmanRCugEvg iy nigRCugxI ix . kugRtaMgkMlaMgkat;TTwgGacRtUv)anKNnaBI

    =

    ii yx

    Tv

    2max

    3 !%>^

    Edlii

    yx 2 CatMlEdl)anBIplbUkmuxkat;ctuekaNEkgtUc. enAeBlEdl 10/ xy eKGaceRbIsmIkarsMrYlxageRkam

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm&

    5> kMlaMgpbrvagkMlaMgkat; nigkMlaMgrmYl Combined Shear and Torsion

    enAkgkrNIGnuvtn_CaeRcIn Ggt;eRKOgbgMGacrgnUvTaMgkMlaMgkat;nigkMlaMgrmYlCamYyKa.kugRtaMgkMlaMgkat;GacnwgekItmanenAkgmuxkat;CamYynwgkugRtaMgkMlaMgkat;mFm 1v= enAkgTis

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 353

    edAnkMlaMgkat;V rUbTI 15>6 a. kMlaMgrmYl TbegItkugRtaMgrmYlenAelIRKb;RCugrbs;muxkat;ctuekaN ABCD rUbTI15>6 a CamYynig 23 vv > . karBRgaykugRtaMgcugeRkayRtUv)anTTYlBI

    karbUkbBalnUv\TiBlnkugRtaMgkMlaMgkat;nigkugRtaMgrmYl edIm,IbegIttMlGtibrmaes

    I 31 vv + enAelIRCug CD b:uEnRCug AB nwgmankugRtaMgcugeRkayesI 31 vv . RCug AD nig BCnwgrgEtkugRtaMgrmYl 2v . muxkat;RtUvd)anKNnasMrab;kugRtaMgGtibrma ( )31 vvv += .

    6> RTwsIkarrmYlsMrab;Ggt;ebtug Torsion Theories for Concrete Members

    eKmanviFICaeRcInsMrab;viPaKGgt;ebtugBRgwgedayEdkEdlrgkarrmYl brgkarrmYl karBt;

    nigkarkat;kgeBlEtmYy. CaTUeTAviFIKNnasMGageTAelIRTwsIeKalBIrKWthe skew bending theory

    nig space truss analogy.6>1> Skew Bending Theory

    viFIeKalrbs;skew bending theoryEdlENnaMeday HsuCaviFIEdlsikSakar)ak;nmuxkat;ctuekaNedaykarrmYlEdlekItedaykarBt;eFobGkSRsbeTAnwgpnmuxkat; y FMCag nigeRTtedaymMu o45 eTAnwgGkSEvgnFwm rUbTI 15>7. QrelIviFIsaRsenH m:Um:g;rmYlGb,brma nT GacRtUv)an

    KNnadUcxageRkam

    rn fyx

    T

    =

    3

    2

    !%>*

    Edl rf KWm:UDuldac;rbs;ebtug. rf RtUv)ansnt;esInwg 12/'5 cf enAkgkrNIenH Edl

    RtUv)aneRbobeFobCamYy 12/'5.7 cf EdlTTYleday ACI CodesMrab;KNnaPaBdabenAkgFwm.

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 355

    =s KMlatEdkkg

    1x nig =1y RbEvgxInigRbEvgEvg KitBIGkSeTAGkSnEdkkgbiTCit bBIEdkenARCug.

    smIkarmunecalnUvlTPaBTb;karrmYlrbs;ebtug. Mitchellnig CollinsENnaMnUvsmIkarxageRkamedIm,IKNnamMurmYlkgmYyktaRbEvg

    ( )

    +

    +

    =

    sin

    2tan

    tan2

    d

    o

    hhl

    o

    o

    P

    P

    A

    P

    !%>!@Edl =l bMErbMrYlrageFob (strain)enAkgEdkbeNay (longitudinal reinforcing steel)

    =h bMErbMrYlrageFobenAkgEdkkg (hoop steel)=d bMErbMrYlrageFobebtugGgt;RTUgenARtg;TItaMgnkMlaMgpbnFarkMlaMgkat;

    (shear flow)=hP brimaRtrbs;EdkkgKitRtwmGkSEdk

    = mMunkMlaMgsgt;Ggt;RTUg ( )

    ++=

    o

    h

    hdld P

    P

    / =oA RkLapEdlBTCMuvijedaykMlaMgkat;b

    q2/torque= Edl =q FarkMlaMgkat;=oP brimaRtnKngFarkMlaMgkat; brimaRtrbs; oA

    smIkarmMurmYlxagelImanlkNRsedogKanwgsmIkarmMukMeNagkgkarBt;rUbTI 15>10

    d

    sc +

    == curvature !%>!#

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm!$

    Edl oA / oP nig s RtUv)anBnl;BIxagelI= sysfA kMlaMg yield nEdkbeNayTaMgGs;

    =hyhfA kMlaMg yield nEdkkg

    ACI Code )anTTYlykRTwsIenHedIm,IKNnaGgt;eRKOgbgMebtugEdlrgkarrmYl bkarrmYlnigkarkat;enAkgviFIsaRsdsMrYl.

    7> ersIusg;rmYlnGgt;ebtugsuT Torsional Strength of Plain Concrete Memgers

    Ggt;ebtugrgkarrmYlCaTUeTARtUv)anBRgwgedayEdkTb;nwgkarrmYlBiess. kgkrNIEdlkugRtaMgrmYlmantMltUc nigRtUvkarKNnasMrab;Ggt;ebtugsuT kugRtaMgkMlaMgkat; tcv GacRtUv)ankMNt;edayeRbIsmIkar !%>^

    2

    '32

    ctc

    f

    yx

    Tv =

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 357

    nigmMurmYlKW yGxTL 3/3= / Edl TCam:Um:g;rmYlEdlGnuvtmkelImuxkat;tUcCagm:Um:g;rmYlEdleFVIeGayeRbH nig G KWCam:UDulkMlaMgkat;nigGacRtUv)ansnt;esInwg 45.0 dgnm:UDuleG-

    Lasicrbs;ebtug cE Edl cfG '2135= . kMlaMgkat;TTwgeFVIeGayeRbHedaysarkarrmYl(torsional cracking shear) cv enAkgebtugsuTGacRtUv)ansnt;esI cf'5.0 . dUcenH sMrab;muxkat;ctuekaNebtugsuT

    cc fyxT '12

    2= !%>!%

    nigsMrab;muxkat;EdlpSMeLIgedayctuekaNEkgeRcIn

    = yxfT cc2'

    12

    !%>!^

    8> karrmYlenAkgGgt;ebtugBRgwgedayEdk Torsion in Reinforced ConcreteMemebers (ACI Code Procedure)

    8>1> sBaaNTUeTA GeneraldMeNIrkarKNnasMrab;karrmYlmanlkNRsedogKaeTAnwgkMlaMgkat;TTwgedaykarBt;. enA

    eBlEdlm:Um:g;rmYlemKuNGnuvtenAelImuxkat;FMCaglTPaBTb;m:Um:g;rmYlkgrbs;ebtugGacTb;)an

    enaHsameRbHEdlekItedaykarrmYl(torsional crack) ekIteLIg dUcenHEdkTb;karrmYl (torsionalreinforcement) kgTMrg;CaEdkkgbiTCit (closed stirrup or hoop reinforcement) RtUv)andak;.bEnmBIelIEdkkgbiTCit EdkbeNaykRtUv)andak;enAtamRCugrbs;Edkkg nigRtUv)anBRgayy:aglenACMuvijmuxkat;. TaMgEdkkgbiTCit nigEdkbeNaymansarsMxan;Nas;kgkarTb;nwgkMlaMgTajGgt;RTUgEdlbNaymkBIkMlaMgrmYl EdkEtmYyRbePTnwgKanRbsiTPaBeTebIKanEdkmYyRbePTeTot. EdkkgRtUvEtbiTCit edaysarkugRtaMgrmYlekItmanenARKb;RCugrbs;muxkat;.

    EdkcaM)ac;sMrab;karrmYlRtUv)anbEnmelIEdkcaM)ac;sMrab;kMlaMgkat;/ sMrab;karBt;nigkMlaMgtamGkS. EdkEdkcaM)ac;sMrab;karrmYlRtUv)andak;edIm,IeFVIeGayersIusg;m:Um:g;rmYlrbs;muxkat; nT FMCagbesInwgm:Um:g;rmYlemKuN uT EdlRtUv)anKNnaBIbnkemKuN.

    un TT !%>!&enAeBleKRtUvkarEdkTb;karrmYl ersIusg;m:Um:g;rmYl nT RtUv)anKNnaedaysnt;kMlaMg

    rmYl uT TaMgGs; RtUv)anTb;edayEdkkg nigEdkbeNayCamYynwgersIusg;Tb;karrmYlrbs;ebtug

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 359

    kgbiTCitxageRkAbMput RtUv)ankMNt;eday ohA pqUtenAkgrUbTI15>11. edaysarGgdTeTotRtUv)aneRbIenAkgsmIkarKNna vakRtUv)anENnaMCadMbUgenATIenHedIm,ICYyeGaykaryl;nUvsmIkarman

    lkNgayRsYl. BIrUbTI 15>11 GgEdleGayRtUv)ankMNt;dUcxageRkam=cpA RkLapmuxkat;ebtugEdlBTCMuvijedaybrimaRtxageRkAnmuxkat;ebtug=cpP brimaRtnmuxkat;ebtugTaMgmUl cpA =ohA RkLapEdlBTCMuvijedayGkSnEdkrgkarrmYlTTwgbiTCitxageRkAbMput pqUtkgrUbTI

    15>11=oA RkLapEdlBTCMuvijedayKngFarkMlaMgkat;TTwg nigGacykesInwg ohA85.0

    =hP brimaRtebtugrbs;EdkrgkarrmYlTTwgbiTCitxageRkAbMput= mMunkMlaMgsgt;Ggt;RTUgcenaH o30 eTA o60 bGacykesInwg o45 sMrab;Ggt;ebtugGarem:

    sMrab;muxkat;GkSr T nig L TTwgRbsiTPaBnsabmagRtUv)ankMNt;esInwgkMBs;FwmEdlsitenABIelIbBIeRkamkMralxNedayykmYyNaEdlFMCag b:uEnminRtUvFMCag 4 dgkMras;kMralxNeTACI Code, Sections 11.6.1 and 13.2.4.

    8>3> m:m:g;rmYleFVeGayeRbH crT Cracking Torsional Moment crT

    m:Um:g;eFVIeGayeRbHeRkamm:Um:g;rmYlsuT crT GacRtUv)anTajecjedayCMnYsmuxkat;BitR)akdmunnwgeRbH CamYynwg thin-walled tubesmmUl cpcp PAt /75.0= / CamYynwgRkLapEdlBTCMuvijedayGkSCBaaMg 3/20 cpAA = . enAeBlEdl kugRtaMgTajGtibrma kugRtaMgem mantMlesI

    3/'cf sameRbHnwgekItman ehIyCaTUeTAm:Um:g;rmYl TesInwgtAT o2= !%>!*

    Edl = kugRtaMgkMlaMgkat;edaykarrmYl 3/'cf= sMrab;sameRbHedaykarrmYl.

    CMnYs eday 3/'cf

    ncp

    cpccr T

    P

    AfT =

    =

    2

    3

    ' nig cru TT = !%>!(

    edaysnt;fam:Um:g;rmYltUcCagbesInwg 4/crT nwgmineFVIeGaymankarkat;bnyersIusg;Tb;karBt; bTb;kMlaMgkat;enAkgGgt;nrcnasm

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm muxkat;!a. mU:m:g;eFVIeGayeRbH crT GacRtUv)anKNnaBIsmIkar !%>!(

    =

    cp

    cpccr

    P

    AfT

    2

    3

    '

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 361

    sMrab;muxkat;enH oocp yxA = RkLapmuxkat;TaMgmUl Edl mmxo 400= nigmmyo 610=

    2244000610400 mmAcp == =cpP brimaRtnmuxkat;ebtugTaMgmUl

    ( ) ( ) mmyx oo 202061040022 =+=+=

    mkNTcr .392020

    244000

    3

    2875.0

    2

    =

    =

    b. nT GnuBaatEdlGacGnuvtedaymineRbI EdkTb;karrmYlRtUv)anKNnaBIsmIkar !%>@0

    mkN

    T

    T

    cr

    a .75.94

    39

    4===

    2> muxkat;@

    a. dMbUgKNna cpA nig cpP sMrab;muxkat;enH nigGnuvtsmIkarTI !%>!( edIm,IKNna crT .edaysnt;sabRtUv)andak;CamYyEdkkgbiTCit enaHsabRbsiTPaBEdlRtUveRbIenARCugmagnRTnugesInwg $dgkMras;sab b ( ) mmhmm w 4004001004 ===

    flangeseffectiveofareaareaweb +=cpA

    22550004001002350500 mmAcp =+= ( ) ( ) mmhbPcp 3300500400235022 =++=+=

    mkNTcr .263300

    255000

    3

    2875.0

    2

    =

    =

    cMNaM RbsinebIsabRtUv)anecal ehIyEdkTb;karrmYlRtUv)andak;EtenAkgRTnugenaH

    2175000500350 mmAcp ==

    ( ) mmPcp 17005003502 =+= mkNTcr .8.23=

    b. nT GnuBaatEdlGacGnuvtedaymineRbIEdkTb;karrmYl

    mkNT

    T cra .5.64

    26

    4===

    3> muxkat;3

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 363

    nkMhUcRTg;RTay (compatibility of deformation) RtUv)anrkSa enAkgGgt;eRKOgbgM.rUbTI15>14 bgajBI]TahrN_sMrab;krNIenH EdlFwmTTwgBIrmanGMeBIelIFwmEKmbegIt

    m:Um:g;rmYl. mMurmYlFMekItman enAeBlsameRbHedaykarrmYlelcecj Edlpl;nUvkarbgEckbnkdFMenAkgeRKOgbgM. vanwgeTAdl;m:Um:g;rmYlEdleFVIeGayeRbH crT eRkamGMeBInbnSMkarBt;karkat;nigkarrmYl enAeBlEdlkugRtaMgem (principle stress) mantMlRbEhl 3/'cf . enAeBlEdl cru TT > m:Um:g;rmYlesInwg crT smIkar !%>!(EdlGacsnt;ekItmanenARtg;muxkat;eRKaHfak;enACitpnTMr.

    ACI CodekMNt;m:Um:g;rmYlKNnaesInwgtMltUcCageKn uT Edl)anBIbnkemKuN b crT

    BIsmIkar !%>!(.

    8>5> karkMNt;nersIsg;m:m:g;rmYl Limitation of Tortional Moment StrengthACI Code,Section 11.6.3kMNt;TMhMmuxkat;edaysmIkarxageRkamBIr!> sMrab;muxkat;tan;

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm@@

    Edl == 6/' dbfV wcc ersIusg;kMlaMgkat;sMrab;ebtugTMgn;Fmta. GgdTeTotRtUv)ankMNt;enAkgEpk 8>2.

    karkMNt;enHKWQrelIPaBCak;EsgEdlfaplbUknkugRtaMgEdlbNalBIkMlaMgkat;nigm:Um:g;

    rmYl GgxageqVg minRtUvFMCagkugRtaMgEdleFVIeGayeRbHbUknwg3/'2 cf

    . krNIdUcKaRtUv)anGnuvtedIm,IKNnakMlaMgkat;edayK

    anm:Um:g;rmYlenAkgemeronTI8. eKRtUvkarkarkMNt; (limitation)edIm,Ikat;bnysameRbH nigedIm,IkarBarEbkpebtugEdlbNalmkBIkugRtaMgkMlaMgkat;TTwgeRTtnigm:Um:g;rmYleRTt.

    8>6> muxkat;Rbehag Hollow SectionbnSMnkugRtaMgkMlaMgkat;nigkugRtaMgm:Um:g;rmYlenAkgmuxkat;RbehagRtUv)anbgajenAkgrUb

    15>6 EdlkMras;CBaaMgRtUvOansn

    t;faefr. enAkgmuxkat;RbehagxH kMras;CBaaMgGacERbRbYlCMuvijbrimaRt. sMrab;krNIenH smIkar !%>@@ RtUv)ankMNt;enATItaMgEdlGgxageqVgmantMlGtibrma. cMNaMfa enAnwgsabxagelI nigsabxageRkam CaTUeTAkugRtaMgkMlaMgkat;RtUv)anecal. CaTUeTA RbsinebIkMras;CBaaMgnmuxkat;Rbehag ttUcCag hoh PA / enaHsmIkar !%>@@ kayCa

    +

    +

    c

    w

    c

    oh

    hu

    w

    u fdb

    V

    tA

    PT

    db

    V'

    3

    2

    7.1 !%>@#

    (ACI Code, Section 11.6.3).

    8>7> EdkRTnug Web ReinforcementdUcEdl)anBnl;rYcehIy viFIACI CodesMrab;KNnaGgt;Edlrgm:Um:g;rmYlKWQrelIspace

    truss analogyenAkgrUbTI15>8. bnab;BIkareRbHedaykarrmYl eKRtUvkarEdkBIrRbePTedIm,ITb;nwgm:Um:g;rmYlEdlGnuvt uT KWEdkTTwg (transverse reinforcement) tA enAkgTMrg;CaEdkkgbiTCit nigEdkbeNay (longitudinal reinforcement) lA . ACI Code)anbgajnUvsmIkarxageRkamedIm,IKNna tA nig lA

    !> EdkkgbiTCit tA EdlGacKNnadUcxageRkam

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 365

    s

    fAAT

    ytton

    cot2= !%>@$

    Edl

    un

    TT = nig 75.0=

    =tA RkLapneCIgmYyrbs;EdkkgbiTCit=ytf ersIusg;yal (yield strength)rbs; tA MPaAt 400

    =s KMlatEdkkg

    oA nig RtUv)ankMNt;enAkgEpk 8>2. smIkar !%>@$ GacRtUv)ansresrdUcxageRkam

    cot2 yto

    nt

    fA

    T

    s

    A= !%>@%

    RbsinebI o45= enaH 0.1cot = nigRbsinebI MPafyt 400= enaHsmIkar !%>@% kayCa

    o

    nt

    A

    T

    s

    A

    800= !%>@^

    Edl nT KitCa mmN. . KMlatEdkkg sminRtUvFMCagntMltUcCageKkgcMeNam 8/hP nigmm300 . sMrab;muxkat; RbehagrgkarrmYl

    cMgayEdlvas;BIGkSnEdkkgeTApxagkgrbs;CBaaMgminRtUvtUcCag hoh PA /5.0 .

    @> EdkbeNaybEnm lA

    EdlcaM)ac;sMrab;karrmYlminKYrtUcCagtMlxageRkam2cot

    =

    y

    yth

    tl

    f

    fP

    s

    AA !%>@&

    Rbsin o45= nig MPaff yyt 400== sMrab;TaMgEdkkg nigEdkbeNayenaHsmIkar !%>@& kayCa

    ( )112 yxs

    AP

    s

    AA th

    tl +

    =

    = !%>@*

    hP RtUv)ankMNt;enAkgEpk 8>2. cMNaMfa EdkEdlcaM)ac;sMrab;karrmYlKYrRtUv)anbEnmBIelIEdlEdlcaM)ac;sMrab;kMlaMgkat; m:Um:g;Bt;nigkMlaMgtamGkSEdleFVIGMeBIrYmKaCamYykMlaMgrmYl. karkMNt;epSgeTotsMrab;EdkbeNay lA mandUcxageRkam

    a. Ggt;pitEdktUcbMputsMrab;EdkbeNayKW 10DB bKMlatEdkkgelI 24 b 24/s edayykmYyNaEdlmantMltUcCageK.

    b. EdkbeNayKYrRtUv)anBRgayCMuvijbrimaRtrrbs;EdkkgCamYyKMlatGtibrma mm300 .

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm8> EdkTb;karrmYlGb,brma Minimum Torsional Reinforcement

    enAkEngNaEdlEdkTb;karrmYlGb,brmaRtUvkar EdkTb;karrmYlGb,brmaRtUv)ankMNt;dUcxageRkam (ACI Code, Section 11.6.5)

    !> EdkkgbiTCitGb,brmasMrab;bnSMnkMlaMgkat;TTwg nigkarrmYl emIlEpk 8>6

    yt

    wtv

    f

    sbAA

    35.02 + sMrab; MPaf c 31' <

    +

    yt

    wctv

    f

    sbfAA '063.02 sMrab; MPaf c 31' !%>@(

    Edl =vA RkLapeCIgTaMgBIrrbs;EdkkgEdlkMNt;)anBIkMlaMgkat;=tA RkLapeCIgEtmYyrbs;EdkkgEdlkMNt;BIm:Um:g;rmYl

    =s KMlatEdkkg=ytf ersIusg;yal (yield strength)rbs;Edkkg MPa400

    KMlatEdkkg s minKYrFMCagtMltUcCagkgcMeNam 8/hP nig mm300 . KMlatenHRtUvkaredIm,IRKb;RKgsameRbH.

    @> RkLapEdksrubGb,brmarbs;EdkbeNayTb;karrmYl

    =

    y

    yth

    t

    y

    cpcl

    f

    fP

    s

    A

    f

    AfA

    '5min

    !%>#0Edl sAt / minRtUvyktUcCag ytw fb /173 .

    lA Gb,brmaenAkgsmIkar !%>#0 RtUv)ankMNt;edIm,Ipl;nUvGRtaGb,brmanmaDEdkTb;kMlaMgrmYlelImaDebtug mantMlRbEhl %1 sMrab;ebtugGarem:EdlrgkMlaMgrmYlsuT.

    9> segbviFIsaRsKNnaeday ACI Code Summary of ACI Code Procedures

    viFIsaRsKNnasMrab;bnSMkMlaMgkat;TTwg nigkMlaMgrmYlGacRtUv)ansegbdUcxageRkam

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 367

    !> KNnakMlaMgkat;TTwgemKuN uV nigm:Um:g;rmYlemKuN uT BIkMlaMgEdlGnuvtmkelIeRKOgbgM. tMleRKaHfak;sMrab;kMlaMgkat;TTwg nigkMlaMgrmYlKWsitenARtg;muxkat;EdlmancM

    gay d BIprbs;TMr.@> a.eKRtUvkarEdkkMlaMgkat;TTwgenAeBl 2/cu VV > Edl 6/' dbfV wcc = .

    b.EdkTb;karrmYlRtUvkarenAeBlEdl

    >

    cp

    cpcu

    P

    AfT

    2

    12

    ' !%>@0

    RbsinebIEdkRTnugRtUvkar GnuvtviFIsaRsxageRkam.

    #> KNnasMrab;kMlaMgkat;TTwga. KNnaersIuisg;kMlaMgkat;nominalEdlpl;edayebtug cV . kMNt;kMlaMgkat;TTwg

    EdlTb;edayEdkRTnug

    scu VVV += b

    cus

    VVV

    =

    b. eRbobeFob sV Edl)anKNnaCamYynwgtMlGnuBaatGtibrma 3/'2 dbf wc eyagtam ACI Code. RbsinebI sV tUcbnkarKNna EtpymkvijtMeLIgTMhMmuxkat;rbs;

    ebtug.c. EdkRTnugkMlaMgkat;TTwgRtUv)anKNnadUcxageRkam

    df

    sVA

    yt

    sv =

    Edl =vA RkLapneCIgTaMgBIrrbs;Edkkg=s KMlatEdkkg

    EdkkMlaMgkat;TTwgkgmYyktaRbEvgKWdf

    V

    s

    A

    yt

    sv =

    d. RtYtBinit sAv / Edl)anKNnaCamYynwg sAv / Gb,brma

    =

    yt

    w

    yt

    wc

    v

    f

    b

    f

    bf

    s

    A35.0'063.0(min)

    vA Gb,brma RtUv)ankMNt;edaybTdaneRkambnSMnGMeBIrbs;kMlaMgkat;TTwg nigkM

    laMgrmYlRtUv)aneGayenAkgCMhanTI5

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm KNnasMrab;karrmYla.

    RtYtBinitfaetIm:Um:g;rmYlemKuN uT begItm:Um:g;rmYllMnwg (equilibrium torsion)

    bm:Um:g;rmYlRtUvKa (compatibility torsion). sMrab; equilibrium torsion eRbI uT .sMrab;compatibility torsionm:Um:g;rmYlKNnaKWtMltUcCageKn uT BIbnkemKuNnig

    =

    cp

    cpcu

    P

    AfT

    2

    23

    ' !%>!(

    b. RtYtBinitfaetITMhMnmuxkat;RKb;RKan;bGt;. vaTTYl)anedayeRbIsmIkar !%>@! sMrab;

    muxkat;tan;bsmIkar !%>@@ sMrab;muxkat;Rbehag. RbsinebItMlenAGgxageqVgFMCag ( )3/'2/ cwc fdbV + enaHbegInmuxkat;pymkvijKNnabn. sMrab;muxkat;Rbehag RtYtBinitfaetIkMras;CBaaMg ttUcCag hoh PA / bGt;. RbsinebIvatUcCageRbIsmIkar !%>@# pymkvijeRbIsmIkar !%>@@.

    c. kMNt;EdkkgbiTCitcaM)ac;BIsmIkar !%>@%

    cot2 yto

    nt

    fA

    T

    s

    A= !%>@%

    sAt / minRtUvtUcCag ytw fb /173 . ehIy mMuGacsn

    t;es

    I o45 / /un TT = nig75.0= .

    snt; ( )1185.085.0 yxAA oho == Edl 1x nig 1y CaTTwg nigkMBs;rbs;muxkat;KitBIGkSeTAGkSEdkkg emIlrUbTI!%>!!. sMrab; o45= nig MPafy 400=

    o

    nt

    A

    T

    s

    A

    800

    = !%>@^

    KMlatGnuBaatGtibrma s KWtMltUcCageKn mm300 b 8/hP .d.

    kMNt;EdkbeNaybEnmBIsmIkar !%>@&

    2cot

    =

    y

    yth

    tl

    f

    fP

    s

    AA !%>@& a

    EtminRtUvtUcCag

    = y

    yt

    h

    t

    y

    cpc

    l f

    f

    Ps

    A

    f

    Af

    A 12

    '5

    min !%>@&b

  • 8/11/2019 15 xv-design-for-torsion

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 369

    sMrab; o45= nig MPafyt 400= enaH ( ) htl PsAA /= !%>@*EdkbeNayTb;karrmYlKYrmanGgt;pity:agticesIKMlatEdkkgelI24 b 24/s b:uEn

    minRtUvtUcCag 10DB . EdkbeNayRtUvdak;enAkgEdkkgbiTCitCamYyKMlatGtibrmaesI mm300 . y:agehaceKRtUvdak;EdkmYyedImenARKb;mMurbs;Edkkg. CaTUeTAmYyPaKbIn Edk lA RtUv)anbEnmeTAelIEdkTaj mYyPaKbIenABak;kNalkMBs;rbs;muxkat;nigmYyPaKbIeTotenAEpksgt;.

    %> kMNt;RkLapsrubnEdkkgbiTCitEdlbNalBI uV nig uT .

    ( )yt

    wtvvt

    f

    sbAAA

    35.02 += !%>@(

    eRCIserIsEdkkgbiTCitsmrmCamYyKMlat s EdlmantMltUcCageKkgcMeNam mm300 nig 8/hP .EdkkgKYrRtUv)andak;enAcMgay )( dbt+ eRkaycMnucEdlRTwsIRtUvkar Edl =tb TTwgnmuxkat;EdlTb;nwgkMlaMgrmYl.

    ]TahrN_ 5>3

    (Equilibrium Torsion)

    kMNt;brimaNEdkRTnugcaM)ac;sMrab;muxkat;ctuekaNEkgdUcbgajenAkgrUbTI15>15. muxkat;rgnUvkMlaMgkat;emKuN kNVu 5.213= nigkMlaMgrmYllMnwg (equilibrium torsion) mkNTu .41= enATItaMgEdlmancMgay dBIpnTMr. eKeGay MPaf c 28' = nig MPafy 400= .

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm

    kMlaMgKNnaKW kNVu 5.213= nig mkNTu .41= 2>a. EdkTb;kMlaMgkat;RtUvkarenAeBl 2/cu VV > .

    ( )( ) kNbdfV cc 6.13710520400286

    75.0'

    6

    3 ===

    kNV

    kNV cu 8.682

    5.213 =>=

    eKRtUvkarEdkTb;kMlaMgkat;.b.

    eKRtUvkarEdkTb;karrmYlenAeBla

    cp

    cpcu T

    P

    AfT =

    >

    2

    12

    '

    2232000580400 mmyxA oocp === ( ) ( ) mmyxP oocp 184052040022 =+==

    ( )mkNTa .7.910

    184012

    2320002875.0 62

    =

    =

    mkNmkNTu .7.9.41 >= EdkTb;kMlaMgrmYlRtUvkarcaM)ac;. cMNaMfa RbsinebI uT tUcCag mkN.7.9 enaHEdkTb;kar

    rmYlnwgminRtUvkar b:uEnEdkTb;kMlaMgkat;RtUvkar.3>KNnakMlaMgkat;TTwg

    a. scu VVV += / kNVs 2.101= b. ( )( ) scs VkNbdfV >=== 8.73352040028

    3

    2'

    3

    2(max)

    c. mmmdf

    VsA

    y

    sv /5.0520400102.101 23 =

    == eCIgBIr

    mmms

    Av /25.02

    2= eCIgmYy

    4>KNnasMrab;karrmYla. kMlaMgrmYlKNna mkNTu .41= . KNnalkNmuxkat;edaysnt;kMras;ebtugkarBar

    Edk mm40 nigeRbIEdkkg 12DB

    ( ) mmx 30864024001 =+=

  • 8/11/2019 15 xv-design-for-torsion

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 371

    ( ) mmy 48864025801 =+= CakarGnuvtn_eKGacsnt; mmbx 901 = nig mmhy 901 =

    211 150304488308 mmyxAoh === 24.12775885.0 mmAA oho ==

    ( ) ( ) mmyxPh 159248830822 11 =+=+= o45= nig 0.1cot =

    b. RtYtBinitPaBRKb;RKan;rbs;muxkat;edayeRbIsmIkar !%>@!

    +

    +

    c

    w

    c

    oh

    hu

    w

    u f

    db

    V

    A

    PT

    db

    V'

    3

    2

    7.1

    2

    2

    2

    kNVc 6.137= nig kNVc 5.183=

    MPa82.11503047.1

    159241000000

    520400

    137600sidehandLeft

    2

    2

    2

    =

    +

    =

    MPaMPa 82.13.3283

    2

    520400

    18350075.0sidehandRight >=

    +

    =

    muxkat;RKb;RKan;c.

    kMNt;EdkkgbiTCitcaM)ac;EdlbNalBIkarrmYlBIsmIkar !%>@%

    cot2 yto

    nt

    fA

    T

    s

    A=

    mkNT

    T un .7.5475.0

    41===

    0.1cot = 24.127758 mmAo =

    mmms

    At /535.04004.1277582

    107.54 26

    =

    = eCIgmYy

    d. kMNt;EdkbeNaybEnmBIsmIkarTI!%>@&

    2cot

    =

    y

    yth

    tl

    f

    fP

    s

    AA

    535.0=s

    At mmPh 1592= MPaff yyt 400== 0.1cot = 272.8511592535.0 mmAl ==

    =

    y

    yth

    t

    y

    cpcl

    f

    fP

    s

    A

    f

    AfA

    12

    '5(min)

    2232000mmAcp = 535.0=sAt MPaff yyt 400==

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm

    kMNt;RkLapEdkkgsrub

    a. sMrab;eCIgmYyrbs;Edkkgs

    A

    s

    A

    s

    A vtvt

    2+=

    EdkkgEdlcaM)ac; mmmAvt /785.025.0535.0 2=+= eCIgmYyeRbIEdk 12DB RkLapmuxkat;rbs;EdkkgsMrab;eCIgmYyKW 2113mm

    mm144785.0

    113stirrupsofspacing == yk mm140

    b. KMlatGtibrma mmPs h 199815928 === b mm300 mYyNaEdltUcCag.KMlatEdleRbIKW mmmm 199140 <

    c. sAvt / Gb,brma mmmmmmf

    b

    yt

    w /785.0/35.0400

    40035.035.0 22 edIm,IrkkarBRgayEdkbeNay cMNaMfa lA srub 272.851 mm= . eRbImYyPaKbIenAEpkxagelI b 29.2833/72.851 mm= edIm,IbEnmenAkgEdkrgkarsgt; sA' . eRbImYyPaKbIdak;enA

    EpkxageRkam edIm,IbEnmBIelIEdkrgkarTaj nigEdkmYyPaKbIeTotdak;enAkMBs;Bak;kNal.a.

    RkLapEdksrubenAEpkxagelIesI 29.5099.283226 mm=+ . eRbI 163DB 2603mmAs =

    b. RkLapEdksrubenAEpkxageRkamesI 27.33629.2838.3078 mm=+ . eRbI 283DB nig 322DB enARCugmMu sA srub 28.3455 mm=

    lA srubEdleRbI ( ) ( ) 27548.30788.3455226603 mm=+=

    c.

    enAkMBs;Bak;kNal eRbIEdk 122DB 2

    226mmAs = bg;srsEdklMGitRtUv)anbgajenAkgrUbTI15>15. KMlatEdkbeNayesInwgmm230 EdltUcCagKMlatEdkGtibrmaEdlRtUvkar 2300mm . Ggt;pitEdkkg 12DB Edl

    eRbIFMCagGgt;pitGb,brma 10DB bKMlatEdkkgelI 24 mms 8.524/ = .]TahrN_ 5>4

    (Compatibility Torsion)edaHRsay]TahrN_TI 15>3 eLIgvij RbsinebIkMlaMgrmYlemKuNCa compatibility torsion.

    dMeNaHRsay

  • 8/11/2019 15 xv-design-for-torsion

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 373

    eyagtamdMeNaHRsaykg]TahrNITI 15>3!> kMlaMgKNnaKW kNVu 5.213= nig compatibility torsion mkNTu .41=

    @> CMhan (a)nig (b)dUcKaenAkg]TahrN_TI15>3. eKRtUvkarEdkRTnug.#> CMhan (c) KWdUcKa.$> KNnasMrab;kMlaMgrmYl

    edaysar compatibility torsion mkNTu .41= enaH uT KNnaRtUvtUvCag mkN.41 b crT RtUv)aneGayenAkgsmIkar !%>!(

    mkN

    P

    AfT

    cp

    cpccr .7.3810

    1840

    232000

    3

    2875.0

    3

    ' 622

    =

    =

    =

    edaysarEt ucr TT 3 edayeRbI mkNTu .7.38= edIm,IkMNt;famuxkat;RKb;RKan;.

    mmms

    At /5.0 2= eCIgmYy279615925.0 mmAl ==

    eRbI (min)852 2 ll AmmA >=

    %> vtA caM)ac; mmm /75.05.025.0 2=+= eCIgmYy

    mms 6.15075.0

    113==

    eRbI mm150 . eRCIserIsEdkbeNay nigEdkkgdUckg]TahrN_TI15>3.]TahrN_ 5>5

    (L-section with Equilibrium Torsion)FwmxagnRbBnkMralxNrbs;GKardUcbgajenAkgrUbTI15>16. muxkat;enAcMgay dBIpnTMrrg

    nUvkNV

    u235=

    nigequilibrium torque mkNT

    u.27=

    . KNnaEdkRTnugcaM)ac;edayeRbIMPaf c 28' = nig MPafy 400= sMrab;RKb;EdkEdleRbIenAkgFwm.

    dMeNaHRsay1>kMlaMgKNnaKW kNVu 235= nig mkNTu .27= 2>a. EdkTb;kMlaMgkat;RtUvkarenAeBl 2/cu VV >

    kNdbf

    V wc

    c 3.105104553506

    2875.0

    6

    ' 3 ===

    kNVV cu 65.522

    =>

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm

    muxkat;RtUvkarEdkTb;karrmYl.3>KNnaEdkTb;kMlaMgkat;TTwg

    a. scu VVV +=

    sV75.03.105235 += kNVs 173=

    b. swcs VkNdbfV >== 8.561'3

    2(max)

    c. mmmdf

    V

    s

    A

    y

    sv /95.0455400

    173000 2=

    == eCIgBIr

    mmms

    Av /475.02

    95.0

    2

    2==

    4>KNnaEdkTb;karrmYl mkNTu .27= a. KNnalkNmuxkat;edaysnt; kMras;ebtugkarBarEdk mm40 nigEdkkg 12DB .

    RTnug ( ) mmx 258124023501 == ( ) mmy 438124025301 == sab mmx 3801= EdkkghYscUleTAkgRTnug

    mmy 58921501 == ( ) ( ) 213504443825838058 mmAoh =+=

    24.11478785.0 mmAA oho == ( ) ( ) mmPh 22684382582380582 =+++= o45=

    0.1cot =

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    T.Chhay NPIC

    karKNnasMrab;kMlaMgrmYl 375

    b. RtYtBinitPaBRKb;RKan;rbs;muxkat;edayeRbIsmIkarTI!%>@! kNVu 235= /kNVc 3.105= / kNVc 4.140= / mkNTu .27=

    MPa47.21350447.1

    22681027

    455350

    235000sidehandLeft2

    62=

    +

    =

    MPa3.3283

    2

    455350

    14040075.0sidehandRight =

    +

    =

    muxkat;manlkNRKb;RKan;c. kMNt;EdkkgbiTCitedIm,ITb;karrmYl sAt / BIsmIkar !%>@%

    mmm

    fA

    T

    s

    A

    yto

    nt /392.0

    4004.114787275.0

    1027

    cot2

    26

    =

    ==

    eCIgmYy

    d. KNnaEdkbeNaybEnmBIsmIkar !%>@* sMrab; MPaf c 400' = nig 0.1cot = 28892268392.0 mmP

    s

    AA h

    tl ==

    =

    minlA BIsmIkar !%>#0 KW2

    min 7.44788940012

    242500285mmAl =

    =

    karcUlrYmrbs;sabRtUv)anecaledaysarTTYl)anlTplxusKatictYc nigtMlBlkm

    ticCag.5>kMNt;RkLapmuxkat;EdkkgbiTCit

    a. sMrab;eCIgmYy

    s

    A

    s

    A

    s

    A vtvt

    2+=

    muxkat;cM)ac; mmmAvt /867.0475.0392.0 2=+= eCIgmYyeRCIserIsEdk 12DB 2113mmAs =

    KMlatEdkkg mm130867.0113

    == eRbI mm125 b. KMlatEdkGtibrma mmPs h 5.283

    8

    2268

    8max === . eRbI mms 125= dUckarKNna.

    c. mmmmmmf

    b

    s

    A

    yt

    wvt /867.0/31.0400

    35035.035.0 22 kMNt;karBRgayrbs;EdkbeNay. lA srubKW 2889mm . eRbImYyPaKbIb

    23.2963/889 mm= enAEpkxagelI EpkkNal nigEpkxageRkam.

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    Department of Civil Engineering viTasanCatiBh ubeckeTskm16. KMlatEdkbeNayKW mmmm 300190 < . Ggt;pitrbs;EdkkgKWmm12 EdlFMCagGgt;pitEdk 10DB bKMlatEdkkgelI 24 mms 2.524/ = .

    bEnmEdkbeNay 12DB enARKb;mMurbs;EdkkgenAkgRTnugFwm nigsabFwm.

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    T.Chhay NPIC