预应力钢筋混凝土T型梁结构设计.doc

《预应力钢筋混凝土T型梁结构设计.doc》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、预应力钢筋混凝土T型梁结构设计1.Known:SpanofSSB:29m；ComputedspanL=27.66m；Designload：VehicularLoad-Ι；PedestrianLoad=3.0kN/m2；CoefficientofImportanceγ0=1.0；Environment：Bridgelocatesinacommonfield,environmentІ;Relativehumidity(averageofperyear)=75％；Materials：Tendon:lowrelaxationstrands(1×7)；Standardvalueoftens

2、ionstrength；designvalueoftensionstrength；nominalarea=140mm2,nominaldiameter15.2mm;elasticmodulus；Strandtaperedofgroupanchors.Nonprestressedreinforcement:HRB400,fsk=400MPa,fsd=330MPa.HRB335：(d<12mm)normalvalueoftensionstrength；designvalueoftensionstrength；Elasticmodulus=2.0×105MPa；Concrete：C50

3、；=3.45×104MPa；normalvalueofcompressstrength＝32.4MPa；designvalueofcompressstrength＝22.4MPa；normalvalueoftensionstrength＝2.65MPa；designvalueoftensionstrength＝1.83MPa.Designrequirements：JTGD62-2004,TotalPrestressConcrete.Construction：Post-tension;Pre-castgirder;TDJack;Cast-in-sitewetconnectionjo

4、intwithwidthof400mm;Asphaltlayerwith80mmthickness.2.Sizeunit:mm3：Geometricfeaturesofallcross-section1):Calculationofeffectivewidthbf´,obtainingminimumvalueofthefollowingthreeones:(1):Simplesupportedbeamspan’sl/3,l/3=27660/3=9220mm;(1):Averagedistanceofthetwoadjacentbeams,tothemiddlebeamis2200

5、mm;(2):(b+6bh+12hf´),bh=0,wecanlethf́isequivalentwithaverageofwebthicknessaboutmiddlespansection.So,wehaveso(b+6bh+12hf´)=200+6×0+12×228=2936mm;Sobf´=2200mm;2):Calculatinggeometricfeaturesofallcross-section:Generally,geometricfeaturesofmainbeamoftenuseblocknumericalsummationmethod,Areaofallcr

6、osssection:A=AiDistancebetweengravitycenterlineoftheallcrosssectionandthetopofbeam:yu=Aiisareaofblock,isdistancebetweengravitycenterlineoftheallcrosssectionandthetopofbeamTheallcross-sectiongeometricfeaturesofmiddlespansectionshownFigure1.Geometricfeaturesofallcrosssectionfrommiddlespanand1/4

7、spansectionnumberofblockareaofblockAi(mm2)yi(mm)si=Ai*yi(mm3)yu-yi(mm)Ix=Ai*(yu-yi)2(mm)Ii(mm4)Figureoflocksection13600009032400000454972000000unit:mm29600022021120000324770000003320000800256000000-256420000153330660000-9894400000058000017001