预应力混凝土T梁桥端部锚固区拉压杆模型及配筋设计-林波

第39卷增刊(II)2009年11月东南大学学报(自然科学版)JOURNALOFSOUTHEASTUNIVERSITY(NaturalScienceEdition)Vo.l39Sup(II)Nov.2009T林波刘钊郑和晖王景全(,210096):根据有限元应力分析结果,抽象出力流传递路径,提出了T梁端部锚固区拉压杆模型的构形方法.通过对劈裂应力的数值积分,计算合力作用点位置,并将其作为拉杆位置确定的依据.分析表明,由于T梁端部锚固力的合力对截面形心的偏心距不大,劈裂应力合力作用点至锚固端的距离与梁高的比值,基本不受锚下预加力大小梁高以及翼板宽度变化的影响,大小稳定在0.67~0.69之内.最后,应用该构形方法,得到了跨度为20~50m的T梁端部锚固区拉压杆模型,将由拉压杆模型计算出的劈裂力大小与精细化有限元分析结果进行了比较,其比值分布在1.16~1.34范围之内,由此可见,由拉压杆模型给出的劈裂力计算值与有限元分析结果之间相差不大,且偏于安全.:拉压杆模型;劈裂力;端部锚固区;配筋设计;有限元分析:U448.35;TU318.1:A:1001-0505(2009)(II)-0118-08Strut-and-tiemodelsforendanchoragezonesinprestressedconcreteT-sectiongirderbridgesandreinforcementdesignLinBoLiuZhaoZhengHehuiWangJingquan(KeyLaboratoryofConcreteandPrestressedConcreteStructuresofMinistryofEducation,SoutheastUniversity,Nanjing210096,China)Abstract:Accordingtotheresultsofthefiniteelementanalysis,loadpathsweredrawnandstru-tand-tiemodels(STMs)forendanchoragezonesinT-sectiongirderbridgeswereproposed.Throughintegratingtheburstingstressesalongthetendonaxis,thelocationoftheresultantburstingforcewasobtained,whichwastakenasabasistodeterminethelocationofties.Theresultsshowthatbecausetheeccentricityoftheresultantanchoringforcefromthecenterofthegirdersectionisnotgrea,ttheratioofthespacebetweentheresultantburstingforceandtheanchortothegirderheightisintherangeof0.67to0.69andalmostnotinfluencedbyparameterssuchasthemagnitudeofthetendonforce,thegirderheightandtheflangewidth.Finally,theSTMsforendanchoragezonesinT-sectiongirderbridgeswithspanvaryingfrom20to50mwereconstructed.Atthesametime,toevaluatetheprecisionoftheSTMsforburstingforcespresentedinthispaper,acomparisonwascarriedoutbetweentheresultsfromtheSTMsandthoseofthefiniteelementsolutions.TheresultsindicatethatthemagnitudesofburstingforcesobtainedbytheSTMsareclosetothoseobtainedbyfiniteelementanalysisandtheratiosbetweenthemareintherangeof1.16to1.34.Keywords:stru-tand-tiemode;lburstingforce;endanchoragezone;reinforcementdesign;finiteelementanalysis:2009-11-20.:(1981)),,;(),,,,,[e-mail].:(50778038)(20070286097).T,20~50m.,,,,,,,.T,.T11.5,.,,,,,.,,,[1].AASHTO[2],,,,1.5,.,T,[3],T,,T,.,BD[4].T,,D.D,[5-7]T,,,,.T,,T,.11.1,,.,BD,,BD,,,.,,[4].T,.,D,T.1.2TT,,,.170cmT,112.C50,s15.2mm,1.395GPa.1T(:cm)1/mh/mbh/cmtw/cmc1/cmc2/cm201503218106120302004020107180402505020112250503006420113320119增刊(II)林波,等:预应力混凝土T梁桥端部锚固区拉压杆模型及配筋设计2/cm(N1)(N2)(N3)(N4)d1/cmd2/cmd3/cmd4/cmA1/(b)A2/(b)A3/(b)A4/(b)20766104713776530999154106547774012129920014695457775501212122@9240180120607775AASHTO1~1.5,T,,,,,,T,,,,1.5[3].,,,T2,33.2T3T,,,,,T,,N1,.,T,[4],,.5,,,,.T,,[6],,,.[3,6],,T,,3,T,dbi/h,…db/h0.67~0.69.,,(4),,.120东南大学学报(自然科学版)第39卷3/mbf/cmh/cmdb1/hdb2/hdb3/hdb4/h…db/h201701500.740.670.570.67301702000.760.710.520.67401702500.770.730.710.470.69501703000.790.780.730.450.67:…db=EidbiTbi/EiTbi.41.3TT,,,,,,,,.1.3.1腹板平面内的拉压杆模型T:.,T.T:¹D..,.,,,2,,(5).º.,,,,T,,,,[6],,.T,,,121增刊(II)林波,等:预应力混凝土T梁桥端部锚固区拉压杆模型及配筋设计,0.67,db=0.67h.,,a/2[5](a).».,,.,/0,,.[8-10],2,.¼.,6.,RhP3cosA3,27,N2,7,7(a),,,,,,,,.7(a),210,6~10,7(b),,Vb2~10,6~10.30mT,,7b,,,.56(P3cosA3Rh)7(P3cosA3Rh)1.3.2腹板厚度方向以及翼板平面内的拉压杆模型,T,,,[3,5-6],,,.[2],89,P,Rf.122东南大学学报(自然科学版)第39卷891.4.,As=Tbfy(1),As;Tb;fy.AASHTO.,,:¹;º2.5db,1.5;»;¼24300mm.22.1T,T,10.,,,(4),,1.16~1.34,,,.10T(:mm)123增刊(II)林波,等:预应力混凝土T梁桥端部锚固区拉压杆模型及配筋设计4kN/m205216033070285640910122050106014002.230mT10(b)1112,,,513.11T(:mm)12T(:mm)5/kN856385140/MPa280280280/mm230571375500/mm23611188462813(:mm)31).1,,,T,.2),.,,,0.67~0.69,.3),.,20~50mT.124东南大学学报(自然科学版)第39卷,1.16~1.34,,,.(References)[1].JTGD62)2004[S].:,2004.[2]AASHTO.AASHTOLRFDBridgedesignspecifications[S].3rded.WashingtonDC:AmericanAssociationofStateHighwayandTransportationOfficials,2004.[3]SongwutH.Linearandnonlinearfiniteelementanalysesofanchoragezonesinpos-ttensionedconcretestructures[D].Blacksburg,USA:TheVirginiaPolytechnicInstitute,CivilandEnvironmentalEngineeringDepartmen,t2004.[4],,,.[J].,2008,10(10):14-21.LiuZhao,LuZhitao,HuiZhuo,eta.lReviewofapplicationandresearchonstru-tand-tiemodelsforconcretebridges[J].EngineeringSciences,2008,10(10):14-21.(inChinese)[5]MaZG,SalehMA,TadrosMK.Optimizedpos-ttensioninganchorageinprestressedconcreteI-beams[J].PCIJourna,l1999,44(2):56-73.[6]BreenJE,BurdetO,RobertsC,eta.lAnchoragezonereinforcementforpos-ttensionedconcretegirders[R].Austin,Texas:UniversityofTexasatAustin,1991.[7]RogowskyDM,MartiP.Detailingforpos-ttensioned[R].Bern,Switzerland:VSLInternationalLtd,1996.[8]SchlaichJ,Sch¾ferK,JenneweinM.Towardaconsistentdesignofstructuralconcrete[J].JournalofthePrestressedConcreteInstitute,1987,32(3):74-150.[9]LiangQQ,UyB,StevenGP.Performance-basedoptimizationforstru-ttiemodelingofstructuralconcrete[J].JournalofStructuralEngineering,2002,128(6):815-823.[10]LiangQQ,XieYM,StevenGP.Topologyoptimizationofstru-tand-tiemodelsinreinforcedconcretestructuresusinganevolutionaryprocedure[J].ACIStructuralJourna,l2000,97(2):322-332125增刊(II)林波,等:预应力混凝土T梁桥端部锚固区拉压杆模型及配筋设计