矮墩三跨刚构—连续组合梁桥力学性能分析

发布时间：2018-01-19 22:17

本文关键词： 矮墩三跨刚构-连续组合梁桥有限元收缩徐变预应力损失　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国桥梁事业快速发展，预应力混凝土连续梁桥和预应力混凝土连续刚构桥已经成为最常见和广泛应用的两种桥型。然而这两种桥型都有其适用的局限性，连续梁桥需要设置支座，而连续刚构桥的主墩虽不用设置支座，但其内力受温度变化和混凝土收缩徐变等因素影响很大。针对这两种桥型各自的特点，出现了一种将连续刚构桥和连续梁桥组合的新型桥梁结构体系，并称之为刚构-连续组合梁桥。刚构-连续组合梁桥通常是在一联连续梁中部一跨或者数跨采用桥墩和主梁固结的形式，其余边部数跨设置支座的连续梁结构。由于这种桥梁体系是连续梁桥和连续刚构桥组合而成的结构形式，它兼顾了两者的优点同时摒弃了单一结构的缺点，因此在结构受力、使用性能有着一定的优越性。对以往的矮墩大跨桥梁结构，通常选用连续梁桥作为主要桥型设计方案。本文以赞比亚西尔马大桥为工程背景，并运用Midas-Civil有限元分析软件分别建立了矮墩三跨刚构-连续组合梁桥和连续梁桥两种梁桥模型，通过对比分析，总结出矮墩三跨的刚构-连续组合梁桥的特殊的力学性能，主要完成的工作如下： 1）介绍刚构-连续组合梁桥在国内外的发展概况和构造特点，归纳总结出连续梁桥、刚构-连续组合梁桥、连续刚构桥的各自的优缺点，简述了刚构-连续组合梁桥发展的方向和存在的问题，然后提出本文所研究的主要内容。 2）以赞比亚西尔马大桥为工程背景，通过Midas-Civil有限元分析软件，分别建立了矮墩三跨刚构-连续组合梁桥和连续梁桥分析模型，在各种设计荷载及最不利荷载组合作用下，对两种桥型主梁内力、位移及应力分布情况对比分析，并对两种桥型进行结构应力、抗裂性及挠度验算，，通过本文的研究，分析总结出矮墩三跨刚构-连续组合梁桥的力学性能。 3）矮墩三跨刚构-连续组合梁桥受桥墩不均匀沉降、混凝土的收缩徐变、预应力损失、环境温度变化等各种因素影响比较大，分析总结出在各种因素作用下，该桥型应力和挠度的变化情况，并找出受力的最不利截面位置，得出相关结论。
[Abstract]:With the rapid development of bridges in China, prestressed concrete continuous beam bridges and prestressed concrete continuous rigid frame bridges have become the two most common and widely used bridges. Continuous beam bridge needs to be supported, but the main pier of continuous rigid frame bridge does not need to be supported, but its internal force is greatly affected by temperature change and concrete shrinkage and creep. A new type of bridge structure system, which combines continuous rigid frame bridge and continuous beam bridge, is presented, which is called rigid frame continuous composite beam bridge. Rigid frame-continuous composite beam bridge is usually in the middle of a continuous beam one span or several spans of the bridge pier and main beam consolidation form. Because this kind of bridge system is composed of continuous beam bridge and continuous rigid frame bridge, it takes into account the advantages of both and abandons the shortcoming of single structure. Therefore, in the structural force, performance has certain advantages. For the previous long-span bridge structure with short piers, the continuous beam bridge is usually selected as the main bridge design. This paper takes Silma Bridge in Zambia as the engineering background. The Midas-Civil finite element analysis software is used to establish two kinds of beam bridge models, which are the three-span rigid frame-continuous composite beam bridge with low pier and the continuous beam bridge respectively, and the comparison analysis is carried out. The special mechanical properties of the rigid frame-continuous composite beam bridge with short piers and three spans are summarized. The main work accomplished is as follows: 1) introduce the development and structural characteristics of rigid-continuous composite beam bridge at home and abroad, sum up the advantages and disadvantages of continuous beam bridge, rigid frame-continuous composite beam bridge and continuous rigid frame bridge. In this paper, the development direction and existing problems of rigid-frame continuous composite beam bridges are briefly described, and the main contents of this paper are put forward. 2) taking the Silma Bridge in Zambia as the engineering background, through the Midas-Civil finite element analysis software, the analysis models of the three-span rigid frame-continuous composite beam bridge with low pier and continuous beam bridge are established respectively. Under the combination of various design loads and most unfavorable loads, the internal force, displacement and stress distribution of the two kinds of bridge girder are compared and analyzed, and the structural stress, crack resistance and deflection of the two kinds of bridges are checked and calculated. Through the research in this paper, the mechanical properties of three-span rigid-frame-continuous composite beam bridge with short pier are analyzed and summarized. 3) Three-span rigid frame-continuous composite beam bridge with short piers is affected by various factors such as uneven settlement of pier, shrinkage and creep of concrete, loss of prestress, change of environment temperature and so on. The variation of stress and deflection of the bridge is analyzed and summarized under the action of various factors, and the most unfavorable section position of the force is found out, and the relevant conclusions are drawn.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441

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