桥梁工程PPT(姚林森第二版)第2篇第4章

1、第二篇 钢筋混凝土和预应力混凝土简支梁桥第4章 装配式简支梁桥的设计与构造Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology本章内容 4.1 装配式简支梁桥的构造类型 4.2 装配式钢筋混凝土简支梁桥 4.3 装配式预应力混凝土简支梁桥 4.4 组合梁桥 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology(1)截面型式 Section

2、 4.1 装配式简支梁桥的构造类型（第1章已讲）装配式简支梁桥的截面型式可分为：形、形、T T形和箱形形和箱形。形T形箱形Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式简支梁桥的截面形式，开始讲解这个知识点a.施工稳定性好，安装较方便；b.腹板薄，配筋通常只能采用钢筋网片，难以形成骨架；c.钢筋用量相对较多，构件重量较大；d.通常采用钢筋混凝土(RC)，适用跨径为612m。 4.1 装配式简支梁桥的构造类型(1)截面型式 Section 形截面的

3、特点：形Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology武汉理工大学交通学院 制作：陈小佳a.制造简单；b.肋内配筋可以做成钢筋骨架；c.整体性较好，接头方便;d.施工稳定性差，运输和安装较复杂；e.构件在桥面板的跨中接头，对板的受力不利；f.采用RC时，适用跨径为4.520m； 采用PC时，适用跨径为2040m。 4.1 装配式简支梁桥的构造类型(1)截面型式 Section T形截面的特点：断面Dept of Road & Bridge Engineerin

4、g, School of Transportation, Wuhan University of Technologya.抗扭刚度大，偏心荷载下梁的受力较均匀；b.横向抗弯刚度大，稳定性好；c.制作较复杂，重量相对较大。 SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.1 装配式简支梁桥的构造类型(1)截面型式 Section 箱形截面的特点：箱形Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配

5、式简支梁桥的截面形式，讲解结束块件划分的原则a.技术可行：预制、吊装、运输条件b.受力较小：接缝的位置c.施工简单：接缝的数量d.力求标准化块件划分方式a.纵向竖缝b.纵向水平缝c.纵、横向竖缝 SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.1 装配式简支梁桥的构造类型(2)块件划分 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：预制拼装块件的划分，开始讲解这个知识点纵向竖缝 AAA-A沿纵向的

6、竖缝 g恒载应力Mg+p活载应力Mp=g + p应力总和SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.1 装配式简支梁桥的构造类型Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologyAAg恒载应力MgA-A沿纵向的水平缝 +p活载应力Mpp=g + p应力总和pSCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.1 装配式简支梁桥的构造类型纵向水平缝 Dep

7、t of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.1 装配式简支梁桥的构造类型纵、横向竖缝 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：预制拼装块件的划分，讲解结束本章内容 4.1 装配式简支梁桥的构造类型 4.2 装配式钢

8、筋混凝土简支梁桥 4.3 装配式预应力混凝土简支梁桥 4.4 组合梁桥 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology（1）构造布置（构造原理）SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点

9、：装配式钢筋混凝土简支梁桥构造布置，开始讲解这个知识点主梁布置P76横隔梁布置（1）构造布置bl/2l/2l/4l/4b端横隔板中横隔板1/4横隔板AAA-ABBB-BSCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology主梁及横隔梁布置实例SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHE

10、N4.2 装配式钢筋混凝土简支梁桥（1）构造布置Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（1）构造布置Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTAT

11、ION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（1）构造布置Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式钢筋混凝土简支梁桥构造布置，讲解结束主梁、翼缘板边梁中梁1518cmh=(1/111/16)lh=3/4hRA68cmh/12150220cmSCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（2）截面尺寸的拟定Dep

12、t of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式钢筋混凝土简支梁桥截面尺寸的拟定，开始讲解这个知识点横隔板16cm梁高h=3/4hR14cmSCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥横隔板Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technolog

13、ySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technologyn 图例SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan Unive

14、rsity of Technology知识点：装配式钢筋混凝土简支梁桥截面尺寸的拟定，讲解结束n 主筋n 主筋的弯起n 分布钢筋n 其它构造钢筋n 保护层SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（3）钢筋构造Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式钢筋混凝土简支梁桥钢筋构造，开始讲解这个知识点SCHOOL OF TRANSPORTATION, WUT

15、 PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式钢筋混凝土简支梁桥钢筋构造，讲解结束P81 干接头 湿接头SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（4）装配式主梁的连接构造Dept of Road & Bridge Engineering, School of Transportati

16、on, Wuhan University of Technology知识点：装配式主梁的连接构造，开始讲解这个知识点n 湿接头实例 连接前 连接后 SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.2 装配式钢筋混凝土简支梁桥（4）装配式主梁的连接构造Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式主梁的连接构造，讲解结束本章内容 4.1 装配式简支梁桥的构造类型 4.2 装配式钢筋混凝土简支梁

17、桥 4.3 装配式预应力混凝土简支梁桥 4.4 组合梁桥 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology（1）构造布置SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式预应力混凝土简支

18、梁桥构造布置，开始讲解这个知识点n 端部梁肋加厚n 梁肋下部加宽成马蹄形n 翼缘板加宽（1）构造布置SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology（1）构造布置SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bri

19、dge Engineering, School of Transportation, Wuhan University of Technologyn 图例（1）构造布置SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式预应力混凝土简支梁桥构造布置，讲解结束n 核心截面概念 SCHOOL OF TRANSPORTATIO

20、N, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥（2）截面尺寸拟定Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式预应力混凝土简支梁桥截面尺寸的拟定，开始讲解这个知识点SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transporta

21、tion, Wuhan University of Technology（2）截面尺寸拟定PPhx=0s=01/3h1/3h1/3h核心距kSCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology（2）截面尺寸拟定n 截面上受正弯矩和轴向力作用时,弯矩的作用等效于轴向力上移一段距离： P hePMe = M / PSCHOOL OF TR

22、ANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology（2）截面尺寸拟定4.3 装配式预应力混凝土简支梁桥（2）截面尺寸拟定4.3 装配式预应力混凝土简支梁桥 假定跨中截面，截面特征如上 。 在预加力阶段，当施加偏心预应力Ny时，由于梁的反拱，跨中截面因梁本身的重量而产生弯矩Mg1，该弯矩的作用使得Ny的作用点上移e，作用在下核心点，截面上缘达到零应力状态。

23、Nye=Mg1（Mg1抵消上缘拉应力弯矩）（2）截面尺寸拟定4.3 装配式预应力混凝土简支梁桥（2）截面尺寸拟定 在运营阶段，随着后期横载（桥面铺装，人行道和栏杆等）弯矩Mg2和活载弯矩Mp的作用，预加力合力点将进一步上移，只要预应力大小适宜，就能使得其作用位置正好处于上核心点，此时计及预应力损失Ny后截面内力Ny=Ny-Ny，移动的距离为k=ku+ko（k即为核心距），此时截面下缘应力为零。 平衡方程为（Mg2+Mp使Ny上移到上核心点，随Ny的上移，要使下缘不产生拉应力，必须使在后续荷载作用下，满足）： （Ny-Ny）（ku+ko）=Mg2+Mp下缘拉应力抵消弯矩 下缘拉应力弯矩n 结论a

24、.截面设计中应使截面的形心位置要高，以加大偏心距e，从而节省预应力筋的数量； e= Mg1 / Ny Ny e= Mg1b.截面核心距的大小体现了运营阶段承受荷载的能力，而且核心距k值越大，预应力筋就越节省； ko+ky= (Mg2 + Mp ) / ( Ny - Ny ) ( Ny - Ny )(ko+ky)= (Mg2 + Mp )SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥（2）截面尺寸拟定Dept of Road & Bridge Engineering, School of Transporta

25、tion, Wuhan University of Technologyn 截面效率指标 = k / h 。 通常希望在0.45到0.5之间。n 好的预应力T形梁设计，应当是截面效率指标大，形心位置高。一般地说，腹板愈薄， 值也愈大；马蹄愈小，翼缘愈宽，则形心位置越高。hb1ba. h=（1/16 1/18 ）lb. h=（0.150.2） h c. b=1.82.3md. b=0.140.18me. b1=(2.03.0) bf. 马蹄区管道保护层厚度6cmh.马蹄面积不宜少于全截面的10%12%bh45SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X

26、J CHEN4.3 装配式预应力混凝土简支梁桥（2）截面尺寸拟定Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式预应力混凝土简支梁桥截面尺寸的拟定，讲解结束武汉理工大学交通学院 制作：陈小佳4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology (3)纵向预应力筋布置特点n 索界图 核心距

27、K的概念是集中力作用于两核心之间时，界面上下边缘将不出现拉应力。如果说允许截面出现不大于规定拉应力值（部分预应力），那么同样可找出上、下两个特征点，我们称之为上、下限心点，分别以Co和Cu表示，显然限心距CoCu大于核心距K。 按前面“截面效率指标”同样的分析方法可知，外荷载的增加，等价于预加力位置的上移。因此束界可按如下的方法确定。 知识点：装配式预应力混凝土简支梁桥配筋特点，开始讲解这个知识点武汉理工大学交通学院 制作：陈小佳4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan

28、 University of Technology确定方法： 从下限心点Cu向下量取Mg1/Ny所得的曲线为索界下限【依据： Nye=Mg1（Mg1抵消上缘拉应力弯矩） 】，再从上限心点Co向下量取 M/Ny所得的曲线为索界上限【依据： （Ny-Ny）（ku+ko）=Mg2+Mp 】。 位于上限时，下缘等于规定拉应力。 位于下限时，上缘等于规定拉应力。 h=(Ny Ny)ftCoNyk上限心点CuNyft下限心点张拉阶段运营阶段抗拉极限强度SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥上、下限心点和索界 D

29、ept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology上限心点下限心点CoCuMg1M=Mg1+Mg2+MpMg1 / Ny(Mg2+Mp )/ NySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technologyn 索界

30、图 武汉理工大学交通学院 制作：陈小佳4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology n 减余剪力图 预应力Ny剪力抵消恒载、活载剪力（Qg+p）后的剪力图 预应力筋的锚固分两种情形：在先张法梁中，钢丝或钢筋主要靠混凝土的握裹力锚固在梁体内；在后张法梁中则通过各类锚具锚固在梁端或梁顶。SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥n 纵向预

31、应力筋的锚固 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technologya.先张法的锚固 先张法梁中预应力钢丝端段的应力传递。SCHOOL OF TRANSPO

32、RTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology 钢丝锚结SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Techno

33、logyb.后张法的锚固 后张法中锚具底下的混凝土劈裂力。 SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology 后张法中梁端锚固区的配筋构造。SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN1.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Enginee

34、ring, School of Transportation, Wuhan University of Technology后张法也可以采用带有预埋锚具的预制钢筋混凝土端板来锚固预应力筋。SCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥(4) 构造实例p95Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTATION, WUT PRODUCE

35、D BY：X J CHEN4.3 装配式预应力混凝土简支梁桥(4) 构造实例p96Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of TechnologySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥(4) 构造实例 A caseDept of Road & Bridge Engineering, School of Transportation, Wuhan University of Techn

36、ologySCHOOL OF TRANSPORTATION, WUT PRODUCED BY：X J CHEN4.3 装配式预应力混凝土简支梁桥工地现场构造Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology武汉理工大学交通学院 制作：陈小佳4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology武汉理工大学

37、交通学院 制作：陈小佳4.3 装配式预应力混凝土简支梁桥Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology知识点：装配式预应力混凝土简支梁桥配筋特点，讲解结束本章内容 4.1 装配式简支梁桥的构造类型 4.2 装配式钢筋混凝土简支梁桥 4.3 装配式预应力混凝土简支梁桥 4.4 组合梁桥 Dept of Road & Bridge Engineering, School of Transportation, Wuhan University of Technology4.4 组合梁桥 Composite beam bridge 组合梁桥也是一种装配式的桥跨结构，不过它是进一步用纵向水平裂缝将桥梁的梁肋部分与桥面板(翼板)分割开来，桥面板再借纵横向的竖缝划分成平面内呈矩形的预制构件，这样就是单梁的整体截面变成与肋的组合截面。 组合梁桥有钢筋混凝土工形梁、少筋微弯板与现浇桥面的T形组合梁桥、预应力混凝土的T形组合梁桥以及箱型组合梁桥等几种。Dept of Road & Bridge Engineering, School of Transportation, Wuhan Universi