摘要本次设计桥梁类型为预应力混凝土连续梁桥，预应力混凝土连续梁是现在广泛使用的一种体系，主要适用于大跨度梁桥。它具有变形小，结构刚度好，行车平顺舒适，伸缩缝少，养护简易，抗震能力强等优点。而且采用了预应力筋，增加预应力筋能充分发挥高强材料的特性，具有可靠的强度、刚度和抗裂性能，耐久性强，材料可塑性强，便于建筑艺术处理，也容易满足桥梁曲线和坡度的要求。当桥跨增大时，在荷载作用下，连续梁桥的中间节点截面处将承受较大的负弯矩，从绝对值来看，支点负弯矩远大于跨中正弯矩。采用变截面梁（支点处梁高增大，跨中梁高减小，其间按曲线或折线过渡）更能适用结构的内力分布规律。常采用悬臂法施工，变截面梁的受力状态与其施工时的内力状态基本吻合，更适用于大跨度预应力混凝土连续梁桥，其外形和谐，节省材料并可增大桥下净空，是大跨度桥梁的优选方案。本设计包括上部结构布置、梁恒载内力计算、主梁的活载内力计算、确定钢筋面积、预应力损失计算、空心板短暂和持久状态应力验算等。本设计题目为：三跨预应力混凝土空心板型连续梁桥。它具有变形小，结构刚度好，行车平顺舒适，伸缩缝少，养护简易，抗震能力强等优点。而且采用了预应力筋，增加预应力筋能充分发挥高强材料的特性，具有可靠的强度、刚度和抗裂性能，耐久性强，材料可塑性强，便于建筑艺术处理，也容易满足桥梁曲线和坡度的要求。关键词：预应力,内力计算,配筋,验算ABSTRACTThedesignforprestressedconcretecontinuousgirderbridgetypes,prestressedconcretecontinuousbeamisnowwidelyusedasystem,mainlyissuitableforthelargespanbridge.Ithaslittledeformation,structurestiffness,drivingsmoothandcomfortable,lessexpansionjoints,easymaintenance,seismicability,etc.Andthetendons,increasetendonsthatcangivefullplaytothecharacteristicsofthehighstrengthmaterialswithreliablestrength,stiffnessandcrackresistance,durabilitystrong,materialplasticity,facilitatearchitecturalartprocessing,alsoeasytomeettherequirementsofthebridgecurveandslope.Whenthebridgespansincreases,theunderloadofcontinuousgirderbridgeformiddlesectionofthenodewillbearlargerinthenegativemoment,fromabsolutevalueperspective,thefulcruminthenegativemomentfaroutweighthecrossCKSbendingmoment.Thevariablebeamcanbeappliedtotheinternalstructuremoredistributionrule.Oftenthecantileverconstructionmethod,becomebeam'sstressstateanditsconstructionofinternalforceofthestateresults,moresuitabletothelargespanprestressedconcretecontinuousgirderbridge,itsappearanceisharmonious,savematerialandcanincreasetheobstacleclearanceunderthebridge,isthelargespanbridgeoptimization.Thisdesignincludetheupperstructureloadliveloadinternalforceofmaingirderintralforcecalculationcalculateanddeterminethereinforcementareaofprestresscalculationhollowslabisshortandpersistentstatechechking,ect.Th