3×20m-预应力简支空心板桥设计

I黄山市黟县翼然路桥设计摘要本次设计课题为3×20m预应力简支空心板桥施工图设计。预应力混凝土空心板梁桥以结构受力性能好、变形小、伸缩缝少、行车平顺舒适、养护工程量小、抗震能力强等而成为赋予竞争力的主要桥型之一。设计桥梁跨度为3×20m，桥宽18.5m。计算过程大致如下：首先，确定主梁主要构造及细部尺寸，必须与桥梁的规定和施工保持一致，考虑到抗弯刚度及抗扭刚度的影响，设计空心板梁。其次，利用结构设计原理的知识求解分析结构总的内力（包括横载和活载的内力计算）。用于计算的内力组合结果从而估算出纵向预应力筋的数目，然后再布置预应力钢丝束。再次计算预应力损失，然后进一步进行截面强度的验算，其中包括承载能力极限状态和正常使用极限状态。在正常使用极限状态验算中包括计算截面的混凝土法向应力验算，预应力钢筋中的拉应力验算、截面的主应力计算。必须通过多次验算才能得到理想结果，经过多次调节各号钢束的编数根数雨束数以及加配普通钢筋，最终使得结构安全验算合格。最后，通过AUTOCAD绘制了桥梁施工图纸。通过毕业设计，实现了对桥梁工程专业知识的梳理，锻炼了专业技能，提高了综合素质，为进一步学习和工作打下了坚实的基础。关键词：预应力混凝土、简支梁桥、空心板、内力组合、强度验算、AutoCAD。IIYixianCountyHuangshanCitywingranLuqiaodesignAbstractThedesignoftheprojectis3x20mprestressedsimplysupportedhollowslabconstructiondrawingsdesign.Theprestressedconcretehollowslabgirderbridgeisoneofthemaintypesofthebridge,whichhastheadvantagesofgoodstructuralperformance,smalldeformation,lessexpansionjoints,smoothandcomfortabledriving,smallmaintenance,andstrongseismicresistance.Thespanofthebridgeis3x20mandthebridgewidthis18.5m.Thecalculationprocessisasfollows:Firstofall,todeterminethemainstructureofthemaingirderandthedetailsize,mustbeconsistentwiththeprovisionsofthebridgeandconstruction,consideringtheeffectofbendingstiffnessandtorsionalstiffness,thedesignofhollowslabbeam.Secondly,thestructuraldesignprincipleisusedtosolvetheinternalforceofthestructure(includingthecalculationoftheinternalforcesofthetransverseloadandliveload).Usedtocalculatetheinternalforcecombinationresultstoestimatethenumberoflongitudinalprestressingtendons,andthenarrangetheprestressedsteelwirebundle.Thirdly,theprestresslossiscalculated,andthenthecross-sectionstrengthischecked,includingthelimitstateofbearingcapacityandserviceabilitylimitstate.Thecalculationofnormalstressofconcrete,includingthecalculationofthesectionstress,thecheckingofthetensilestressintheprestressedsteelandthecalculationoftheprincipalstressofthesection.Mustbecheckedthroughanumberoftimesinordertogetthedesiredresults,afterseveraltimestoadjustthenumberofthenumberofthenumberofbundlesofsteelbeamsandthenumberofordinarysteelbars,andultimatelymakethestructuralsafetycheckqualified.Finally,throughtheAUTOCADdrawingofthebridgeconstructiondrawings.Throughthegraduationdesign,thebridgeengineeringknowledgehasbeenrealized,theprofessionalskillhasbeenimproved,andthecomprehensivequalityhasIIIbeenimproved,whichhaslaidasolidfoundationforfurtherstudyandwork。KeyWords:PrestressedConcrete;SimpleSupportedBeamBridge;HollowSlab;InternalForceCombination;StrengthChecking;AutoCADIV目录前言........................................................................................................11设计资料.................................................................................................21.1设计参数.............................................................................................21.2桥梁主要材料.....................................................................................22方案比选.................................................................................................32.1设计方案............................................................................................................32.2方案选择.............................................................................................43构造形式及尺寸选择.............................................................................53.1横断面布置.........................................................................................53.2板块结构几何尺寸.............................................................................53.2.1毛截面截面面积.........................................................................................63.2.2毛截面重心位置..........................................................................................63.2.3全截面对截面底边的惯性矩..................................................................73.2.4空心板截面抗扭刚度IT………………………………….…………..…..74作用效应计算.......................................................................................104.1永久荷载作用效应计算...................................................................104.1.1空心板自重（第一阶段结构自重）g.............................................104.1.2桥面系自重（第二阶段结构自重）g.............................................104.1.3铰缝自重g................................................................................................104.2可变作用效应计算...........................................................................11V4.2.1冲击系数和车道折减系数计算............................................................124.2.2汽车荷载横向分布系数..........................................................................134.2.3车道荷载效应计算..................................................................................214.3作用效应组合....................................................................................245预应力钢筋设计...................................................................................275.1预应力钢筋数量的估算....................................................................275.2预应力钢筋的布置............................................................................295.3普通钢筋数量的估算及布置.........................................................