第二篇钢筋混凝土和预应力混凝土梁式桥Part2RC&PCbeambridge第一章Chapter1梁式桥概述IntroductionofthebeambridgeBRIDGEENGRGPARTIIChapter1梁式桥概述Introductionofthebeambridge1.1Classification类型的划分(1)按承重结构的静力体系划分Classificationbasedonthestructuralsystem简支梁桥Simplesupportedbeam连续梁桥bridgeContinuousbeambridge悬臂梁桥CantileverbeambridgeDevelopmentonthestructure结构体系的演变简支梁SimplesupportedbeamSpanincreasing跨度增加qlql2/8ql2/8ql2/8连续梁Continuousbeam悬臂梁Cantileverbeam1.1Classification类型的划分(1)按承重结构的静力体系划分Classificationbasedonthestructuralsystem(2)按承重结构的截面形式划分Classificationbasedonthestructuralsection板桥肋板式梁桥箱形梁桥Chapter1梁式桥概述Introductionofthebeambridge截面形式的演变Evolutionofthesection实心板Solidslab肋板Slabwithribs空心板SlabwithhollowT形梁Tbeam箱梁BoxgirderSpanincreasing跨度增加Chapter1梁式桥概述IntroductionofthebeambridgeChapter2第二章梁式桥设计要点与构造OutlineonthedesignandconstructofbeambridgePart2RC&PCbeambridge第二篇钢筋混凝土和预应力混凝土梁式桥BRIDGEENGRGPARTII1.1简支体系Simple-supportedstructure1.1.1简支板桥Simple-supportedslabbridge建筑高度小Height外形简单,施工安装简便Form跨径不宜过大Span简支板的构造尺寸DimensionofSimple-supportedslab1梁式桥的立面布置Elevationarrangementforbeambridge1.1.简支体系Simple-supportedstructure1.1.2简支梁桥Simple-supportedbeambridge简支梁的构造尺寸DimensionofSimple-supportedbeam1梁式桥的立面布置ElevationarrangementforbeambridgeStandarddimensionofsimple-supportedbeam标准图简支梁的构造尺寸1.1.Simple-supportedstructure简支体系1.1.2Simple-supportedbeambridge简支梁桥1梁式桥的立面布置Elevationarrangementforbeambridge1.2cantileverbeamsystem悬臂体系1.2.1RCcantileverbeambridge钢筋混凝土悬臂梁桥Singlespanwithtwocantilevers单孔双悬臂梁桥TsectionT形截面lx=(0.3~0.4)lBoxgirder箱形截面lx=(0.4~0.6)lHhllxlx1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系ThreespanwithcantileversandahangBeam三跨带挂梁单悬臂梁桥l1=(0.6~0.8)llg=(0.4~0.6)lh=(1/12~1/20)lgH=(1.5~1.8)hHhll1l1lg1.2.1RCcantileverbeambridge钢筋混凝土悬臂梁桥1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系Multi-spanwithdoublecantileversandhangbeams多跨带挂梁双悬臂梁桥l1=(0.75~0.8)llg=(0.5~0.6)lll1lgHhllg1.2.1RCcantileverbeambridge钢筋混凝土悬臂梁桥TsectionT形梁Boxgirder箱形梁h=(1/12~1/20)lh=(1/12~1/20)lH=(1.5~1.8)hH=(1.0~1.5)h1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系1.2.2PCcantileverbeambridge预应力混凝土悬臂梁桥PCcantileverbeambridgeismoresuitableforlargespanofmorethan50m跨度超过50m以上,采用预应力混凝土悬臂梁桥更合理。l1=(0.5~0.8)lh=(1/20~1/25)llg=(0.2~0.4)lH=(1.0~1.5)hll1lgHhllg1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系由于施工阶段的受力与结构使用状态下的受力的一致性,T形刚构桥常是经济的方案。全桥的T形单元尺寸尽可能相同,以简化设计与施工;T形刚构的布置应尽可能对称,以避免T形刚构的桥墩承受不平衡弯矩。1.2.3PCrigid-framebridge预应力混凝土T形刚构桥1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系Structuralarrangementofrigid-frame刚构的布置形式:1.2.3PCrigid-framebridge预应力混凝土T形刚构桥1梁式桥的立面布置Elevationarrangementforbeambridge1.2Cantileverbeamsystem悬臂体系T形刚构支点、跨中梁高与跨径的关系:带铰T形刚构l≤100mH=(1/14~1/22)lh=(0.20~0.4)H且h≤1.0m带挂梁T形刚构l≥100mH=(1/17~1/21)lh=(0.20~0.4)H且h≤1.5m1.2.3PCrigid-framebridge预应力混凝土T形刚构桥1梁式桥的立面布置Elevationarrangementforbeambridge1.3Continuousbeamsystem连续体系Mid-span中间跨l=8~14mSide-span边跨(0.7~0.8)lHeightonmid-spansection跨中截面高h=(1/18~1/30)lHeightonsupportedsection支点截面高H=(1.2~1.5)h1.3.1Continuousslabbridge连续板桥1梁式桥的立面布置Elevationarrangementforbeambridge1.3Continuousbeamsystem连续体系不等跨变截面连续梁布置(以三跨为例)边跨(0.6~0.8)l支架施工可取0.8l悬臂施工可取0.65l折线形变截面支点截面高H=(1/16~1/20)l,跨中截面高h=(1/22~1/28)l曲线形变截面支点截面高H=(1/16~1/20)l,跨中截面高h=(1/30~1/50)l等跨等截面连续梁布置截面高h=(1/15~1/30)l,常用h=(1/18~1/20)l1.1.1Continuousbeambridge连续梁桥1梁式桥的立面布置Elevationarrangementforbeambridge2designandconstructoftheslabbridge板桥的设计与构造2.1formofthesimple-supportedslabbridge简支板桥的构造Sectionofslab板桥的截面形式Solid实心板Irregularshape异形板Integral整体式Assemble装配式Solid实心板Hollow空心板(1)Reinforcementdetail配筋构造:主筋不小于φ12mm7~20cm且两侧边缘板带的主钢筋数量,宜较中间2/3板宽范围内板带增加15%分布筋不小于φ6mm25cm保护层厚度不小于2cm深入支点的主筋总量不少于跨中主筋总量的1/4,且间距不少于每米3根2.1.1Cast-in-siteslabbridge整体式板桥2.1Constructofthesimple-supportedslabbridge简支板桥的构造2.1.1Cast-in-siteslabbridge整体式板桥(2)实例Acase标准跨径6m,桥面净宽-7m+2x0.2m,汽车-20级,挂车-1002.1Constructofthesimple-supportedslabbridge简支板桥的构造2.1.2Constructionoftheprefabricatedslab装配式板桥的构造装配式板桥分实心板和空心板标准图实心铰接板跨径为:1.5m、1.0m,1.5m,2.0m,3.0m,4.0m,6.0m和8.0m桥面净宽按照老规范有净-7和净-9两种。2.1Constructofthesimple-supportedslabbridge简支板桥的构造2.1简支板桥的构造2.1.2Constructionoftheprefabricatedslab装配式板桥的构造标准图实心铰接板实例2.1Constructofthesimple-supportedslabbridge简支板桥的构造2.1.2Constructionoftheprefabricatedslab装配式板桥的构造Transverseconnection装配式板桥的横向联接企口混凝土铰连接钢板连接企口混凝土铰连接钢板连接2.1.1Staticcharacteristicoftheskewbridge斜交板桥的受力特点力的传递规律正交简支板斜交简支板2.2Featuresoftheskewbridge斜交板桥的特点2.1.1Staticcharacteristicoftheskewbridge斜交板桥的受力特点受力特点①斜跨径lφ的简支斜板的纵向主弯矩比同宽、跨径lφ的正交简支板之值小,并随斜交角φ的增大而减小;φbb②在与钝角的平分线相垂直的方向上,具有较大的负弯矩,并随斜交角φ的增大而增大,其分布范围不宽并迅速消减;①②③支撑边上的反力很不均匀,在两钝角部分的支座压力要大得多,而锐角处反力较小,甚至出现负反力(上翘);lφ2.2Featuresoftheskewbridge斜交板桥的特点lφ2.1.2Constructionfeaturesoftheskewslab斜交板桥的构造特点整体式斜交板城市板桥lφ与b较接近(lφ/b1.3)两钝角之间,配置主筋垂直于支撑边;分布筋与支撑边平行;靠近自由边,主筋延斜边布置,与两钝角之间主筋完全衔接。2.2Featuresoftheskewbridge斜交板桥的特点2.2Featuresoftheskewbridge斜交板桥的特点2.1.2Constructionfeaturesoftheskewslab斜交板桥的构造特点装配式斜交板板宽b=99cm,一般lφ/b1.3当φ=25~35°,平行四边形布置;当φ=40~60°,主筋延斜边布置,分布筋两钝角之间垂直于主筋,在支撑边附近着平行于支撑边;φ=40~60°φ=25~35°3.1Constr