大跨度刚构—连续组合体系梁桥主梁疲劳性能分析与长期下挠预测研究

发布时间：2018-04-26 15:12

本文选题：刚构—连续组合体系梁桥 + 疲劳　；参考：《长沙理工大学》2014年硕士论文

【摘要】：随着我国交通事业的迅速发展,大跨度预应力混凝土桥梁的建造技术日趋成熟,且造价经济、行车舒适、便于养护,因而得到广泛应用。但在运营过程中,出现了各种形式的病害,严重影响桥梁结构的使用性能,其中以腹板斜裂缝和跨中下挠最为严重。针对这一情况,本文以湘府路湘江大桥为工程背景,对其疲劳性能与长期下挠问题进行研究,主要完成了以下工作：(1)介绍了预应力混凝土刚构—连续组合体系梁桥的发展历程,以及此类桥型的优点和主要的病害情况。(2)通过对各国混凝土疲劳验算相关规范的比较,总结了各国规范中混凝土结构疲劳验算的特点。建立了有限元分析模型,采用各国的验算规范对主梁正截面进行疲劳验算。经对比发现,按照国内规范进行正截面疲劳验算相比BSEN规范和CEB-FIP规范偏保守。(3)运用桥梁专用有限元分析软件Midas/Civil,研究了纵向预应力损失、系统温度变化、刚度降低、收缩徐变等因素对该桥长期挠度影响。分析结果表明,纵向预应力损失是引起桥梁下挠的最主要因素,其中顶板束预应力损失比底板束预应力损失的影响更大；混凝土收缩徐变也是桥梁长期下挠的主要影响因素；结构刚度损失对桥梁下挠有-定的影响；整体升降温对桥梁挠度影响较小。(4)根据本文的分析结果,从设计、施工等不同阶段提出了防治预应力混凝土连续刚构桥跨中长期下挠的措施。
[Abstract]:With the rapid development of transportation in our country, the construction technology of long-span prestressed concrete bridge is becoming more and more mature, and the cost is economical, the driving is comfortable and easy to maintain, so it is widely used. However, in the process of operation, there are various kinds of diseases, which seriously affect the performance of bridge structure, among which the web slanting crack and mid-span deflection are the most serious. In view of this situation, this paper takes Xiangjiang Bridge of Xiangfu Road as the engineering background, studies its fatigue performance and long-term deflection problem, mainly accomplishes the following work: 1) introduces the development course of prestressed concrete rigid frame-continuous composite system beam bridge. And the advantages and main diseases of this type of bridge. (2) by comparing the relevant codes of fatigue calculation of concrete structures in different countries, the characteristics of fatigue calculation of concrete structures in national codes are summarized. The finite element analysis model is established, and the fatigue calculation of the normal section of the main beam is carried out by using the checking codes of various countries. By comparison, it is found that compared with BSEN code and CEB-FIP code, the fatigue checking calculation of normal section is carried out according to the domestic code. (3) the longitudinal prestressing loss, system temperature change and stiffness decrease are studied by using the bridge special finite element analysis software Midas / Civil. The effect of shrinkage, creep and other factors on the long-term deflection of the bridge. The results show that the longitudinal prestress loss is the most important factor to cause the bridge deflection, among which the prestressed loss of roof beam is more important than that of the bottom beam, and the shrinkage and creep of concrete is also the main factor affecting the long-term deflection of the bridge. The influence of structural stiffness loss on bridge deflection and the influence of global rise and cooling on bridge deflection are small. (4) according to the analysis results of this paper, the design, At different stages of construction, the measures to prevent and cure the long-term deflection of prestressed concrete continuous rigid frame bridge are put forward.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.4

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