40米预应力混凝土简支T形梁桥设计

I摘要预应力混凝土梁式桥在我国桥梁建筑上占有重要的地位，在目前，对于中小跨径的永久性桥梁，无论是公路桥梁或者城市桥梁，都在尽量采用预应力混凝土梁式桥，因为这种桥梁具有就地取材，工业化施工，耐久性好，适应性强。整体性好以及美观等多种优点。本设计采用简支T梁结构，其上部结构由主梁、横隔梁、行车道板和桥面部分等组成，显然主梁是桥梁的主要承重构件。其主梁通过横梁和行车道板连接成为整体，使车辆荷载在各主梁之间有良好的横向分布。桥面部分包括桥面铺装、伸缩装置和栏杆等组成，这些构造虽然不是桥梁的主要承重构件，但它们的设计与施工直接关系到桥梁整体的功能与安全，这里在本设计中也给予了详细的说明。本设计主要受跨中正弯矩的控制，当跨径增大时，跨中由恒载和活载产生的弯矩将急剧增加，是材料的强度大部分为结构重力所消耗，因而限制的起跨越能力，本设计采用40m标准跨径，合理地解决了这一问题。在设计中通过主梁内力计算、应力钢筋的布置、主梁截面强度与应力验算、行车道板等设计，完美地构造了一座预应力混凝土简支T梁桥，所验算完全符合要求，所用方法均与新规范相对应。本设计重点突出了预应力在桥梁中的应用，这也正体现了我国桥梁的发展趋势。关键词:预应力混凝土简支T梁后张法施工IIAbstractTheprestressedconcretebeamplatebridgeoccupiesmyimportantstatusinourcountrybridgeconstruction,inatpresent,regardingsmallspanpermanentbridge,regardlessofisthehighwaybridgeorthecitybridge,allasfaraspossibleisusingtheprestressedconcretebeamplatebridge,becausethiskindofbridgehasmakesuseoflocalmaterials,theindustrializationconstruction,thedurabilityisgood,compatible,integritygoodaswellasartisticandsoonmanykindsofmerits.ThisdesignusessimplesupportTbeamstructure,itssuperstructurebythekingpost,septumtransversumbeam,thelaneboardandthebridgefloorpartandsooniscomposed,theobviouskingpostisthebridgemaincarrier.Itskingpostconnectsintothewholethroughthecrossbeamandthelaneboard,enablethevehiclesloadtohavethegoodtraversebetweenvariouskingposts.Bridgefloorpartincludingcompositionsandsoonflooring,expansionandcontractioninstallmentandparapet,thesestructuresalthoughisnotthebridgemaincarrier,buttheirdesignandtheconstructionrelatesthebridgewholedirectlythefunctionandthesecurity,herehasalsogiventhedetailedexplanationinthisdesign.Thisdesignmainlystepsthesaggingmomentcontrol,whenthespanincreases,crossthebendingmomentwhichproducesbythedeadloadandtheliveloadthesharpgrowth,isthematerialintensitymajorityofconsumesforthestructuregravity,thuslimitsthespanningability,thisdesignusesthe40mstandardspan,hassolvedthisproblemreasonably.Inthedesignthroughthekingpostendogenicforcecomputation,thestresssteelbararrangement,kingpostsectionintensityandstresscheckingcalculation,laneboardandsoondesigns,astructureprestressedconcretesimplesupportTbeambridge,thecheckingcalculationcompletelyhasconformedtotherequirementperfectly,usesthemethodandthenewstandardcorresponds.Thisdesignhashighlightedthepre-stressedwithemphasisinthebridgeapplication,thishasalsobeenmanifestingourcountrybridgetrendofdevelopment.Keywords:Pre-stressedconcreteSimplesupportTbeamPosttensionedconstructionI摘要...................................................................IAbstract..............................................................II第一章预应力混凝土简支T形梁桥设计....................................11.1桥梁跨径及桥宽..................................................11.2设计荷载........................................................11.3材料规格........................................................11.4设计依据........................................................11.5基本计算数据....................................................1第二章截面设计......................................................32.1主梁间距与主梁片数..............................................32．2主梁跨中截面尺寸拟订...........................................52.2.1主梁高度......................................................52.2.2主梁截面细部尺寸..............................................52.2.3计算截面几何特征..............................................72.2.4检验截面效率指标（希望在0.5以上）.......................9第三章主梁作用效应计算.............................................103.1永久作用效应计算...............................................103.1.1永久作用集度................................................103.1.2永久作用效应.................................................113.2可变作用效应计算...............................................133.2.1冲击系数和车道折减系数.......................................133.2.2计算主梁的荷载横向分布系数...................................133.2.3车道荷载取值.................................................193.2.4可变作用效应.................................................193.3主梁作用效应组合...............................................24第四章预应力钢束数量估算及其布置...................................254.1跨中截面钢束的估算和确定.......................................254.2预应力钢束的布置...............................................26第五章计算主梁截面几何特性.........................................355.1截面面积及惯矩计算.............................................355.2截面静距计算...................................................365.3截面几何特性汇总...............................................40第六章主梁界面承载力与应力计算.....................................426.1持久状况承载能力极限状态承载力验算.............................426.1.1正截面承载力验算.............................................426.1.2斜截面承载力验算.............................................456.2持久状况正常使用极限状态抗裂性验算.............................506.2.1正截面抗裂性验算.............................................506.2.2斜截面抗裂性验算..............................................51第七章主梁变形验算.................................................567.1计算由荷载引起的跨中扰度验算...................................56第八章横隔梁计算....................................................578.1作用在跨中横隔梁上的可变作用...................................57II8.2截面配筋计算..................................................