预应力混凝土连续梁桥加固技术研究

发布时间：2018-03-31 07:35

本文选题：预应力混凝土连续梁桥　切入点：加固　出处：《长安大学》2015年硕士论文

【摘要】：上世纪中后期,世界各国建设了大量的预应力混凝土连续梁桥。目前,国内外建设的大跨度预应力混凝土连续梁桥普遍存在梁体开裂和跨中下挠的问题。本论文以我国目前现存的预应力混凝土连续梁桥现状出发,分析了预应力混凝土连续梁桥的常见病害,通过有限元软件对大跨度预应力混凝土连续梁桥的跨中下挠的影响因素进行分析。针对预应力混凝土连续梁桥跨中下挠和梁体开裂,在总结该类桥梁常见上部结构及下部结构加固方法的基础上,通过对河南某预应力混凝土连续梁桥采用附加拱式加固体系进行加固分析,并重点阐述了附加拱式加固方法的基本原理、施工方法、施工关键步骤。具体研究的内容主要包括:1)通过对预应力混凝土连续梁桥主要病害(箱梁开裂和跨中下挠)的成因进行详细的分析,并对主要病害提出了相应的处理措施。2)本文分析预应力混凝土连续梁桥的跨中下挠的影响因素,并重点分析了混凝土的收缩徐变、预应力损失、结构刚度降低对预应力混凝土连续梁桥跨中下挠进行有限元模拟分析。结果表明,混凝土收缩徐变、预应力损失以及结构刚度降低是影响预应力混凝土连续梁桥跨中下挠的重要因素。3)在总结预应力混凝土连续梁桥常见加固方法的基础上,阐述了附加拱式加固法,并通过与其他加固方法作对比,本研究对预应力混凝土连续梁桥的跨中下挠问题采用附加拱式加固方法,并重点介绍该加固方法的基本原理与构造理论、有限元模拟过程、施工方法及关键施工工序。4)通过对某一病害桥梁为工程研究背景,对其病害采用附加拱式加固法实现加固,并通过对其加固前、加固后的模型进行静力分析及动力分析,重点分析比较加固前后的应力及变形。结果表明附加拱式加固法可以有效改善桥梁的内力状态,抑制跨中持续下挠,提高桥梁的服务水平,延长桥梁的使用寿命。
[Abstract]:In the middle and late of last century, a large number of prestressed concrete continuous beam bridges were built around the world. The problems of beam cracking and mid-span deflection are common in long-span prestressed concrete continuous beam bridges built at home and abroad. This paper starts from the existing situation of prestressed concrete continuous beam bridges in China. This paper analyzes the common diseases of prestressed concrete continuous beam bridge, and analyzes the influencing factors of mid-span deflection of long-span prestressed concrete continuous beam bridge by finite element software, aiming at the mid-span deflection and beam body cracking of prestressed concrete continuous beam bridge. On the basis of summing up the common superstructure and substructure reinforcement method of this kind of bridge, the reinforcement analysis of a prestressed concrete continuous beam bridge in Henan Province is carried out by using additional arch reinforcement system. The basic principle and construction method of the additional arch reinforcement method are expounded in detail. The key steps of construction. The specific research contents mainly include: 1) through the detailed analysis of the causes of the main diseases of prestressed concrete continuous beam bridge (box girder cracking and mid-span deflection), In this paper, the influencing factors of the deflection of prestressed concrete continuous beam bridge are analyzed, and the shrinkage and creep of concrete and the loss of prestressing force are analyzed. The finite element simulation analysis of the deflection of prestressed concrete continuous beam is carried out by reducing the stiffness of the structure. The results show that the shrinkage and creep of concrete are obtained. The loss of prestress and the reduction of structural stiffness are the important factors affecting the deflection of prestressed concrete continuous beam bridge span. 3) on the basis of summing up the common reinforcement methods of prestressed concrete continuous beam bridge, the additional arch reinforcement method is expounded. By comparing with other reinforcement methods, this study adopts the additional arch reinforcement method for the deflection problem of prestressed concrete continuous beam bridge, and introduces the basic principle and construction theory of the reinforcement method and the process of finite element simulation. Construction method and key construction procedure .4) through the engineering research background of a diseased bridge, the additional arch reinforcement method is used to reinforce the disease, and the static and dynamic analysis of the model before and after reinforcement is carried out. The stress and deformation of the bridge before and after reinforcement are analyzed and compared. The results show that the additional arch reinforcement method can effectively improve the internal force state of the bridge, restrain the continuous deflection in the span, improve the service level of the bridge, and prolong the service life of the bridge.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72

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