波形钢腹板PC组合小箱梁顶推施工技术研究

发布时间：2018-06-25 05:25

本文选题：波形钢腹板 + 分条分块预制组拼　；参考：《华东交通大学》2017年硕士论文

【摘要】：顶推施工作为一种相对成熟的施工工艺,在预应力混凝土梁桥以及钢箱梁的架设中得到了较为广泛的应用。波形钢腹板组合箱梁作为一种新型钢混组合结构,目前在国内外已修建100余座。虽然桥型的选择和施工的方法很多,但顶推施工在此类梁桥中的应用却并不常见,相应的研究也较为薄弱。为此,本文以井山经济技术开发区深圳大桥为例,设计了波形钢腹板PC组合小箱梁,提出组合小箱梁分条分块预制组拼顶推施工方案,分别运用大型有限元软件Midas/Civil和ANSYS开展了顶推施工全过程和主梁顶推施工局部应力分析,相应的研究成果可为同类桥梁的设计和施工提供参考。本文主要完成了以下几方面的工作:(1)综述了顶推施工的发展历程、受力特点及在各种桥型上的运用情况;介绍了波形钢腹板组合梁桥的特点、优势以及国内外的发展概况,总结了波形钢腹板运用顶推法施工的优势以及特点。(2)以井冈山经济技术开发区深圳大桥为例,通过引入波形钢腹板和Φ21.8大直径预应力束,设计了波形钢腹板小箱梁,提出了波形钢腹板箱梁预制组拼顶推的施工方案,实现了梁桥上部结构和下部结构的同时施工,大大提高顶推施工速度,缩短施工工期。(3)运用大型有限元Midas/Civil软件建立顶推施工全过程分析模型,探讨了顶推施工中主梁受力、导梁挠度变化以及使用过程中结构安全性能。顶推施工模拟表明,主梁顶、底板在顶推过程中均有一定的压应力安全贮备,最大压应力出现在底板,其值为19.84MPa,腹板最大剪应力为79.23MPa,均满足规范要求;导梁最大挠度值为172.18mm,约为顶推长度(49m)的1/285,施工中应采取相应措施确保导梁安全通过临时墩。成桥整体受力分析表明,主梁顶、底板均有一定的压应力安全贮备,且最大压应力为16.6MPa,腹板剪应力最大为113.21MPa,均满足规范要求。(4)应用有限元法对顶推施工过程中导梁刚度、自重以及临时墩位置进行优化分析,结果表明导梁重量相对于导梁刚度主梁受力更敏感,在满足导梁刚度的情况下,应尽量减轻导梁的重量。此外,临时墩位置能有效减少主梁内力峰值以及导梁前端挠度峰值,在条件允许的情况下,临时墩应尽量设置在跨中位置。(5)借助有限元程序ANSYS建立波形钢腹板小箱梁全桥有限元模型,选取主梁出现最大负弯距以及最大正弯矩工况进行局部应力分析,结果表明箱梁顶、底板均保持较好的压应力水平,且最大压应力为21.6MPa,波形钢腹板最大剪应力为82.5MPa,均满足规范要求。
[Abstract]:As a relatively mature construction technology, push-push construction has been widely used in the erection of prestressed concrete beam bridges and steel box girders. As a new type of steel-concrete composite structure, more than 100 composite box girders have been built at home and abroad. Although there are many methods of bridge selection and construction, the application of push-push construction in this kind of girder bridge is not common, and the corresponding research is relatively weak. Therefore, taking the Shenzhen Bridge of Jingshan Economic and technological Development Zone as an example, this paper designs PC composite small box girder with corrugated steel webs, and puts forward the construction scheme of prefabricated assembly and pushing construction of composite small box girder in strips and blocks. The whole process of the jacking construction and the local stress analysis of the main beam pushing construction are carried out by using the large-scale finite element software Midas / Civil and ANSYS respectively. The corresponding research results can provide a reference for the design and construction of the similar bridges. The main work of this paper is as follows: (1) the development course, force characteristics and application in various bridge types of jacking construction are summarized, and the characteristics, advantages and development situation at home and abroad of composite girder bridge with corrugated steel webs are introduced. The advantages and characteristics of waveform steel web construction by pushing method are summarized. (2) taking the Shenzhen Bridge in Jinggangshan Economic and technological Development Zone as an example, the small box girder with waveform steel web and 桅 21.8 large diameter prestressed beam is designed. The construction scheme of precast box girder with corrugated steel webs is put forward, which realizes the construction of the superstructure and the substructure of the beam bridge at the same time, and greatly improves the speed of the jacking construction. (3) using Midas / Civil software of large finite element to establish the whole process analysis model of jacking construction, and discussing the force of main beam, deflection change of guide beam and safety performance of structure in the process of using. The simulation of jacking construction shows that the top and bottom of the main beam have some safe storage of compressive stress, the maximum compressive stress appears in the bottom plate, its value is 19.84 MPA, and the maximum shear stress of web plate is 79.23 MPA, which all meet the requirements of the code. The maximum deflection of the guide beam is 172.18mm, which is about 1 / 285of the thrust length (49m). The corresponding measures should be taken in the construction to ensure the safety of the guide beam passing through the temporary pier. The analysis of the whole force of the bridge shows that the top and bottom of the main beam have a certain amount of safe storage of compressive stress, and the maximum compressive stress is 16.6 MPA, and the maximum shear stress of web plate is 113.21 MPa, which all meet the requirements of the code. (4) the stiffness of the guide beam in the process of jacking construction is satisfied with the finite element method, and the maximum compressive stress is 16.6 MPA and 113.21 MPa respectively. The results show that the weight of the guide beam is more sensitive than that of the main beam with the stiffness of the guide beam, and the weight of the guide beam should be reduced when the stiffness of the guide beam is satisfied. In addition, the position of temporary piers can effectively reduce the peak internal force of the main beam and the peak deflection of the front end of the guide beam. The temporary piers should be located in the middle of span as far as possible. (5) the finite element model of the whole bridge with corrugated steel web small box girder is established with the help of finite element program ANSYS. The maximum negative bending distance and the maximum positive bending moment of the main girder are selected for local stress analysis, and the results show that the box girder top is the top of the box girder. The maximum compressive stress of bottom plate is 21.6 MPA and the maximum shear stress of corrugated steel web is 82.5 MPA.
【学位授予单位】：华东交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.462

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