空腹式连续刚构桥适应性与角隅节点模型试验研究

发布时间：2018-04-18 06:43

本文选题：空腹连续刚构桥 + 角隅节点　；参考：《山东大学》2015年硕士论文

【摘要】：连续刚构桥整体性能好、行车舒适、承载能力强、外表美观且经济合理,所以长期以来为广大桥梁工程师所青睐,但是,随着峡谷、山区等不同复杂地形线路的增加,在其相应的建设方面,仍然存在一些不足,如跨越能力有限,不能适应跨径220-300m以上的需求；结构承载效率不高；纵向预应力损失过大,易出现变形开裂下挠问题,影响大桥的耐久性等。本文在传统连续刚构桥的基础上,采用新的设计理念,将主梁根部(墩梁结合处)设计成空腹,成功的突破了普通连续刚构桥的跨径—设计出了主跨290m的北盘江空腹式连续刚构桥—大桥。但是作为一种新桥型,有很多方面需要进一步研究。因此,本文以北盘江空腹式连续刚构桥为研究背景,采用有限元分析、模型试验以及现场监测相结合的手段,对空腹式连续刚构桥适应性及关键节点受力特性等开展相关研究。1、对北盘江大桥在施工阶段及运营阶段的适应性问题进行了研究。利用有限元空间分析,对空腹式连续刚构桥及与其跨度相同、满足现行设计规范的实腹桥变形特点、动力及静力下的关键截面内力情况以及自振特性等进行了对比分析。分析结果表明：空腹式连续刚构桥在施工阶段与成桥阶段适应性均要高于普通连续刚构桥。2、对角隅节点受力特性进行了研究。利用模型试验与有限元分析相结合的手段,分析了正常使用极限状态最不利荷载组合下角隅节点的应力数值和应力分布规律,验证了北盘江大桥角隅节点构造设计的合理性；根据试验及有限元分析结果,掌握了角隅节点复杂应力水平及应力分布规律,找出了受力薄弱点,提出了改进措施；在模型试验基础上,利用有限元计算,开展了汽车荷载的超载模拟,得出了北盘江大桥的容许超载系数,为控制超载提出了理论依据。3、对空腹式连续刚构桥新型交叉锚固布索方式进行了研究。为了解决空腹式连续刚构桥跨径大带来的通长索纵向预应力损失过大的问题,提出了新型交叉锚固布索方式。利用有限元软件对交叉锚固索与通长索在自身应力特性,梁体应力特性,梁体挠度等方面进行了对比分析,对交叉锚固索在超大跨径空腹式连续刚构桥的适应性进行了评定。研究结果表明,交叉锚固新型布索方式相对于传统的通长索布置方式,对下挠的控制作用效果明显,且增加了梁体本身的应力储备,能够有效减小大跨桥梁的纵向预应力损失。4、实际工程应用研究。基于北盘江大桥适应性分析、角隅节点模型试验研究以及新型交叉锚固布索方式研究,将北盘江空腹式连续刚构桥应用到了实际工程中,通过现场线形及应力监测结果与有限元结果对比分析可知,北盘江大桥设计正确、适应性良好,角隅节点受力合理以及新型交叉锚固布索方式实际可行,北盘江空腹式连续刚构桥这种新桥型能够应用于现场实践。
[Abstract]:Continuous rigid frame bridge has good overall performance, comfortable driving, strong bearing capacity, beautiful appearance and reasonable economy, so it has long been favored by bridge engineers. However, with the increase of different complex terrain lines, such as canyons, mountainous areas, etc.,In its corresponding construction, there are still some shortcomings, such as limited span capacity, unable to meet the needs of span over 220-300m, low carrying efficiency of structure, too large longitudinal prestressing loss, and prone to deformation, cracking and deflection.Affect the durability of the bridge, etc.On the basis of the traditional continuous rigid frame bridge, a new design concept is adopted to design the base of the main beam (the junction of the pier and the beam) as an empty stomach.The span of the common continuous rigid frame bridge was successfully broken-the Beipanjiang continuous rigid frame bridge with the main span of 290 m was designed.However, as a new type of bridge, there are many aspects to be further studied.Therefore, based on the research background of Beipanjiang continuous rigid frame bridge, finite element analysis, model test and field monitoring are adopted in this paper.The adaptability of the continuous rigid frame bridge with empty stomach and the stress characteristics of the key nodes are studied. The adaptability of Beipanjiang Bridge in the construction and operation stages is studied.By using finite element space analysis, the deformation characteristics, dynamic and static internal forces of key sections and natural vibration characteristics of hollow continuous rigid frame bridges with the same span and satisfying the current design code are analyzed.The results show that the adaptability of hollow continuous rigid frame bridge is higher than that of common continuous rigid frame bridge at construction stage and completion stage. The stress characteristics of corner joint are studied.By using the method of model test and finite element analysis, the stress value and stress distribution of corner joint under the most unfavorable load combination in normal use limit state are analyzed, and the rationality of the design of corner joint structure of Beipanjiang Bridge is verified.According to the results of test and finite element analysis, the complex stress level and stress distribution law of corner joint are mastered, the weak points of stress are found out, the improvement measures are put forward, and on the basis of model test, the finite element method is used to calculate,The overload simulation of automobile is carried out, and the allowable overload coefficient of Beipanjiang Bridge is obtained. The theoretical basis for controlling overload is put forward, and the new cross-anchoring cable arrangement mode of continuous rigid frame bridge with empty stomach is studied.In order to solve the problem of excessive loss of longitudinal prestress caused by long span span of hollow continuous rigid frame bridge, a new type of cross-anchoring cable arrangement is proposed.By means of finite element software, the stress characteristics of cross-anchored cable and long-span cable are compared and analyzed, and the adaptability of cross-anchored cable in long-span continuous rigid frame bridge is evaluated.The results show that the new type of cable arrangement with cross-anchoring is more effective in controlling the deflection than that in the traditional arrangement of long cables, and the stress reserve of the beam itself is increased.It can effectively reduce the longitudinal prestressing loss of long span bridge.Based on the adaptability analysis of Beipanjiang Bridge, the research of corner node model test and the study of new cross-anchoring cable arrangement, the Beipanjiang continuous rigid frame bridge is applied to the practical project.Through the comparison and analysis of the results of line shape and stress monitoring and finite element analysis, it can be seen that the design of Beipanjiang Bridge is correct, the adaptability is good, the stress of corner node is reasonable, and the new type of cross-anchoring cable arrangement is practical and feasible.Beipanjiang continuous rigid frame bridge can be used in field practice.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446;U448.23

【参考文献】