【作者】 勾红叶；

【导师】 蒲黔辉；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2010， 博士

【摘要】 早期桥梁多是简单的梁、柱、拱、索之类桥式体系,受力明确、造型清晰。但随着科学技术的发展,生产力水平空前提高,桥梁的发展无论从跨越能力提高的速度、结构形式的组合化趋势,还是各种新型材料的应用和合理配置等多方面都有了充分的展现。V形刚构拱组合体系桥充分利用了梁、拱各自桥式的受力优势,优化了结构的受力,节省了工程量,创新了桥梁的外观,是大型公路、铁路桥梁中值得应用与研究的桥式结构。目前有关V形刚构拱组合桥梁的文献尚不多见,也没有相关文献对其受力行为作过系统深入的分析研究。鉴于以上情况,以小榄水道特大桥为研究背景,系统地开展了大跨度V形刚构拱组合桥受力行为的专项研究。内容主要包括五个部分：1、在收集国内外相关资料和深入分析国内外研究成果的基础上,对大跨度V形刚构拱组合桥的发展与受力特点进行了初步分析,并讨论了其在受力行为研究中存在的问题。以新建铁路广珠城际轨道交通工程小榄水道特大桥为工程背景,提出了进行大跨度V形刚构拱组合桥受力行为研究的课题。2、提出了大跨度V形刚构拱组合桥名义刚度的概念,分析了结构参数对名义刚度的影响,推导出名义刚度理论公式。针对拱梁刚度比的选取及其对结构内力分配的影响进行讨论,分析其对结构内力的影响规律,并得出刚拱柔梁与柔拱刚梁的界定值,为设计人员选取构造参数提供指导。3、基于结构试验模型相似理论,进行静力相似原则的分析和推导,确定模型的相似比,采用模型的基本设计原则,设计并完成了V形墩梁节点模型试验。在选定混凝土、钢筋和钢绞线本构关系的基础上,建立了V形墩梁节点三维非线性有限元模型,将数值计算结果与试验结果进行了对比。分析了多种荷载工况下V形墩梁节点局部应力分布规律,通过绘制负弯矩区钢筋荷载应变曲线以及模型梁的荷载挠度曲线,对V形墩梁节点的非线性受力行为进行了研究,得出了挠度与裂缝行为以及刚度变化规律。4、探讨了大跨度V形刚构拱组合桥的施工方案,在施工过程仿真计算时利用单元生死技术,编制了APDL命令流程序,并考虑了混凝土的徐变特性,建立施工过程仿真计算模型,对先梁后拱分段施工全过程进行了计算研究。同时对结构体系受力及刚度进行了分析研究,分析了收缩徐变对结构内力分配的影响,针对吊杆、拱、梁受力比值进行了讨论。最后系统深入地研究了三片腹板剪应力分布规律,各施工阶段箱梁纵向弯曲正应力,成桥后箱梁纵向弯曲正应力和横向弯曲正应力的分布规律。5、建立了大跨度V形刚构拱组合桥施工控制理论,确定施工误差调整理论和方法,包括对设计参数进行识别和修正,自适应系统控制以及分析系统的运行。通过对小榄水道特大桥施工控制研究,对施工方案的可行性作出评价,确定各施工理想状态的线形和位移,对随后施工状态的线形及位移作出预测。介绍了应力控制截面及测试原理,对关键截面应力控制结果进行了分析研究,使施工沿着设计的轨道进行,保证施工中的安全和结构恒载内力及结构线形符合设计要求,保证施工质量和安全。更多还原

【Abstract】 Most of the bridges in early stage are simple bridge systems of beam, column, arch, cable, etc. The characteristics of this kind of bridge are stressing definitely and clearly modeled. However, as the development of technology and the unprecedented improvement of productivity level, the bridges have fully developed in the speed of span ability improvement, the trend of structure form combination and the application and rational allocation of diversity updated materials. It is worthy applying and researching V-shape rigid frame composite arch bridge in large highway and railway bridges because it makes full use of each superiority of beam and arch, optimizes structural force bearing conditions, saves engineering quantity, and innovates the appearance of bridges. At present, there are still few documents in V-shape rigid frame composite arch bridge and it is not found any relative documents doing systematic research in the mechanical behaviors of the bridges. Considering the situations mentioned above, based on Xiaolan channel super large bridge, the author carries out systematic researches on the mechanical behaviors of long-span V-shape rigid frame composite arch bridge. The dissertation includes five parts mainly:1. Based on collecting and learning correlative knowledge at home and abroad, the author preliminarily analyzes the development and mechanical characteristics of long-span V-shape rigid frame composite arch bridge. The existing problems in the research of mechanical behavior are discussed. Researched on newly built railway Guangzhou-Zhuhai intercity rail transit project Xiaolan channel super large bridge, the author proposes the subject of mechanical behavior research of long-span V-shape rigid frame composite arch bridge.2. The author proposes the definition of nominal rigidity of long-span V-shape rigid frame composite arch bridge, analyzes the effects of structural parameters on nominal rigidity and derives the theoretical equation of nominal rigidity. The author also discusses the selection of the rigidity ratio of arch and beam and the effect of the ratio on the structure internal forces distribution, and analyzes the influence law of the ratio on the structure internal forces. Then the author gets the delimitation value between rigid arch-flexible beam and flexible arch-rigid beam. It provides a guidance of selecting the structural parameters to designers.3. Based on the similitude theory of structural test models, the author analyzes and derives the static similitude principle, determines similitude ratio of the model, completes the V-shape pier-girder joint model tests by adopting basic design principle of the model. Based on choosing the constitutive relationships of concrete, steel and strand, the 3-D nonlinear finite element model of V-shape pier-girder joint is established to compare the results of the model tests with the theoretical ones. The focuse is on the local stress distribution of the V-shape pier-girder joint under various loading modes. Nonlinear mechanical behavior of the V-shape pier-girder joint is also studied by drawing the curve of load-reinforcement strain in negative moment area and load-deflection curve. The deflection and cracking behaviors and the change law of stiffness are obtained.4. The construction scheme of long-span V-shape rigid frame composite arch bridge is discussed. In process of simulation calculation of the construction, the author compiles APDL command flow program by using the unit birth-death technique, establishes simulation calculation model in the construction process. The creep characteristics of concrete are also taken into account. The whole process of beam first-to-arch later stage construction are calculated and studied. At the mean time, the force and rigidity of the structure system are studied, the effects of shrinkage and creep on structural internal forces distribution are analyzed, and the force ratio of the suspender, arch and beam is discussed. Finally, the author does a roughly studies on the three-plate webs’s rule of shear stress distribution, the box girder’s longitudinal bending normal stress on every construction stage, and the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge’s box girder.5. The author establishes the construction control theory of long-span V-shape rigid frame composite arch bridge, determines the adjustment theories and methods of construction errors including identifying and correcting the design parameters, controlling the adaptive system and operating the analysis systems. By researching on construction control of Xiaolan channel super large bridge, the feasibility of the construction program is evaluated, the alignment and displacement in each construction ideal state are determined and the alignment and displacement in the following construction state are predicted. The stress controling sections and the testing principles are introduced and the stress controling results of the criticat sections are researched on to make the construction go along well as designed, make sure the safety during construction, the structural internal force under constant load and structural alignment are complied with the design requirements and the construction quality and safety are ensured.更多还原