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西南交通大学本科毕业设计100+160+100m公路预应力混凝土连续刚构桥设计年级：级学号：姓名：专业：指导老师：2010年6月西南交通大学本科毕业设计第II页西南交通大学本科毕业设计第III页摘要本设计的题目是100+160+100m公路预应力混凝土连续刚构桥设计。由题目可知，连续刚构体系适用于高墩大跨的桥梁，因此除了设计桥梁上部结构而外还应该考虑桥墩的设计。首先,进行桥式方案比选，确定桥跨的布置和主要截面形式，确定施工方案。桥梁横截面采用单箱单室，主梁采用变梁高，梁底曲线为二次抛物线，根据经验公式确定中支点处梁高为10.4m，跨中处梁高为4.0m，中墩与主梁结合部设有横隔板，设计桥墩高50m，为双薄壁墩。施工方法采用应用较为广泛的现浇悬臂平衡施工法，挂篮平衡施工，采取先边合拢再中合拢的方式，悬臂施工节段长度为3.5~4.5m，合拢段长度为2.0m。接下来,运用有限元软件MIDAS/CIVIL建立全桥有限元模型，并进行了施工阶段分析以及成桥分析。用PSC设计估算各个截面的预应力筋用量，并结合内力组合进行了纵向预应力筋设计，按现行规范对桥梁进行了截面验算及变形验算。然后，通过软件计算移动荷载和风荷载等活载作用下桥梁的内力，各项预应力损失和有效预应力，由钢束和混凝土收缩、徐变以及温度、支座沉降等引起的二次内力等，并进行荷载组合、截面强度检算。另外，设计中考虑了“桩土效应”，这使得有限元模型对桥梁施工过程、荷载作用等的模拟更加准确。最后,分别采用反应谱法和时程分析法对桥梁结构进行了抗震分析。关键词：大跨度预应力连续刚构桥悬臂施工抗震西南交通大学本科毕业设计第IV页AbstractThetopicofthisthesisisadesignofprestressedconcretecontinuousrigidframebridgewithspansof100+160+100m.Weknewthattherigidframesystemisusuallyappliedtothebridgewithhighpiersandlongspans.SointhispaperIwilldesignthebridgesuperstructureandthepiers.Thefirststepischoosingthebridgetype,determiningeveryspansandthecross-sectionalshapeofthebridge,andworkoutconstructionschemes.Theshapeofthecross-sectionissinglecellbox,andtheheightsofthebeamarevariational.Thecurveofthebeam’sbottomisacubicparabola.Accordingtotheexperimentalformulas,theheightofthebeamatthemiddlefulcrumis10.4m,andatthemiddlespanis4.0m,themiddlepiersaredoublethinwallpierswithheightof50m.Adopttingthecast-in-sitecantileverbalancemethodwhichiswidelyusedtoday.Themaingirderisconstructedbysymmetriccantileverequilibrium.Sidesfirstandmiddlefollowingistheschemeofclosure.Thelengthofeachsectionofcantileveris3.5~4.5m,thelengthofclosuresectionis2.0m.Next,presentfiniteelementmodelofthewholebridge,bytheMIDAS/CIVILsoftware,anddotheanalysisofconstructionphaseandfinishedphase.UsingPSCtoestimatethereinforcingsteelbar’sdosageofeverycross-section.Anddesignthereinforcingsteelbarscombinewithinternalforcecurve.Then,accordingtocurrentspecifications,checkthestrengthanddeformationofthebeam.Then,usethesoftwaretocomputetheinternalforceswhicharecausedbymovingloads,andthelossofprestress,effectiveprestress.Alsocomputethesecondaryinternalforceswhicharecausedbyconcreteshrinkandcreep,tempretureriseordownandsupportsettlementtocheckthestrengthofthebeam.Also,inthedesign,compactioneffectshavebeenadded,thismadethestimulationofloadsmorerealandmoreaccurate.Atlast,theearthquakeresponsespectrumanalysisandtransientanalysisareaddedtocheckthesthenghofthebridge.西南交通大学本科毕业设计第V页keywords：longspan,prestressed,continuousrigidframebridge,cantileverconstruction西南交通大学本科毕业设计第VI页目录第1章绪论.......................................................81.1预应力混凝土概述.............................................81.2预应力混凝土连续刚构桥.......................................81.3预应力混凝土连续刚构桥的施工方法............................11第2章桥梁总体布置及结构主要尺寸................................132.1方案比选....................................................132.2设计依据及基本资料..........................................142.3桥跨布置....................................................152.4上部结构尺寸拟定............................................162.5下部结构尺寸拟定............................................202.6特殊节段处理................................................23第3章桥梁结构内力计算..........................................253.1概述........................................................253.2模型的建立..................................................263.3桥梁恒载内力计算............................................313.4桥梁活载内力计算............................................35第4章预应力钢筋设计...........................................434.1预应力筋布置................................................434.2纵向预应力筋估算............................................444.3预应力损失及有效预应力计算..................................49第5章次内力计算及内力组合.....................................545.1预应力次内力................................................545.2收缩次内力..................................................555.3徐变次内力..................................................565.4温度次内力..................................................585.5基础不均匀沉降次内力........................................635.6荷载组合....................................................65第6章主要截面验算.............................................716.1强度验算....................................................716.2承载能力极限状态截面验算....................................726.3正常使用极限状态截面验算....................................736.4变形验算....................................................78第7章抗震分析.................................................797.1桥梁结构地震反应分析方法....................................797.2桥梁结构动力特性............................................817.3连续刚构桥的地震反应谱分析..................................887.4连续刚构桥的时程分析........................................92西南交通大学本科毕业设计第VII页第8章主要工程数量.............................................968.1混凝土用量..................................................968.2钢束用量估算................................................978.3锚具用量估算................................................99结论...........................................................101致谢...........................................................102参考文献............