PDF《CJJ》

3 - Contents

1 General provisions.1

2 Terms and symbols.2 2.1 Terms.2 2.2 Symbols.4

3 Basic requirement.11 3.1 General requirement

11 3.2 Structure forms.12 3.3 Actions and actions of combination

12 4 Material.14 4.1 Structional steel

14 4.2 Concrete

15 4.3 Steel bar.15

5 Calculation of construction stage

17 5.1 General requirement

17 5.2 Calculation of stress and limit value.17 5.3 Design of steel beam pre-camber

19 5.4 Calculation of steel beam stability.20

6 Design of untimate limit states

23 6.1 General requirement

23 6.2 Calculation of section bending resistance.23 6.3 Calculation of section shearing resistance.26

7 Design of service ability limit states

27 7.1 General requirement

27 7.2 Calculation of stress and limit value.27 7.3 Calculation of finished bridge camber and live load deformation and limit.28 7.4 Calculation of crack resistance and limit value

29 8 Design of shear conectors.32 8.1 General requirement

32 8.2 Design of shear conectors.32 8.3 Detailing requirement of stud connectors.33

9 Design of continuous Preflex prestressed composite beam with variable cross section

35 9.1 General requirement

35 9.2 Design of the continuous beam

35 9.3 Construction of the continuous beam

36 10 Detailing requirments

39 10.1 Steel beams.39 10.2 First-stage concrete.39 10.3 Second-stage concrete

40 11 Construction equipment.43 11.1 General requirement

43 11.2 Anti-roll device.43 11.3 Loading reaction frame and load platform

44 -

4 - 11.4 Rotatable frame

45 11.5 Checking of construction equipment security

45 12 Construction and acception

47 12.1 General requirement

47 12.2 Apply pre-bending force.47 12.3 First stage concrete construction and release prestress.49 12.4 Flip preflex beam.49 12.5 Transportation ,storage and hoisting.49 12.6 Second stage concrete construction.50 12.7 Quality acceptance.50 Appendix A Geometric parameters and calculation factors.51 Appendix B Calculation method of section stress.56 Appendix C Calculation method of deformation.65 AppendixD Preflexed beam with changed sections…69 Explanation of wording in the code…73 List of quoted standards…74 Addition: Explanation of provisions…75

1 总则 1.0.1 为使预弯预应力组合梁桥的设计、施工符合安全可靠、适用耐久、技术先 进、经济合理、环保和美观的要求,制定本规程. 1.0.2 本规程适用于城镇道路、公路工程及轨道交通中的预弯预应力组合梁桥的 设计与施工. 1.0.3 预弯预应力组合梁桥的设计与施工除应符合本规程外,尚应符合国家及行 业现行有关规范、标准的规定.

2 术语和符号 2.1 术语 2.1.1 预弯梁 preflexed beam 以预弯曲的钢梁作为预加应力的工具,以预弯力将其压平并浇筑一期混凝土,卸 除预弯力后利用钢梁的反弹作用对将处于受拉区的一期混凝土施加预压应力, 以 此形成的半成品梁. 2.1.2 预弯预应力组合梁 preflexed composite beam 在预弯梁上浇筑腹板、上翼板等二期混凝土,由此形成的组合梁. 2.1.3 栓钉连接件 stud connector 用于连接钢梁与一期混凝土、二期混凝土,保证三者共同工作的栓钉. 2.1.4 一期混凝土 first-stage concrete 钢梁在预弯状态下,浇筑在钢梁下翼缘周围的混凝土. 2.1.5 二期混凝土 second-stage concrete 二期混凝土是指在预弯梁上浇筑的混凝土,可以包括腹板混凝土、翼缘板混 凝土以及横隔板混凝土. 2.1.6 钢梁预拱度 pre-camber 钢梁的初始上拱值. 2.1.7 预弯力 preflex force 为将具有初始预拱度的钢梁压平而施加的一对竖向荷载. 2.1.8 拼接施工法 method of fabricated construction on preflexed beam segments 将预弯梁沿长度方向拆分成若干梁段进行运输, 在施工现场再将各预弯梁段 重新连接,并在连接部下翼缘浇筑混凝土,使其形成预弯梁整体的施工的方法. 将预弯梁纵向拆分后的部件称为预弯梁段. 2.1.9 变高度预弯预应力组合梁 variable depth of preflexed composite beam 钢梁腹板变高度的预弯预应力组合梁. 2.1.10 变厚度预弯预应力组合梁 variable steel plate-thickness of preflexed composite beam 钢梁顶板、底板或腹板变厚度的预弯预应力组合梁. 2.1.11 变截面预弯预应力组合梁 variable cross-section of preflexed composite beam 由变厚度钢板或变高度、 变厚度钢腹板组成的工字形钢梁与一期混凝土和二 期混凝土组成预弯预应力组合梁的总称. 2.1.12 预弯预应力组合连续梁 preflexed composite continues beam 由按着恒载剪跨划分的预弯梁段、 中支点组合梁段以及连接段共同构成的纵 桥向连续的预弯预应力组合梁. 2.2 符号 2.2.1 材料性能 Ec ―― 混凝土的弹性模量;