预应力混凝土箱梁桥开裂影响因素分析

发布时间：2018-05-12 18:01

本文选题：预应力混凝土箱梁 + 腹板　；参考：《长安大学》2015年硕士论文

【摘要】：预应力混凝土箱梁桥因其整体性强、抗扭刚度大、适应多种现代化的施工方法等一系列的优点,成为很多桥梁选型时的首选。但是随着越来越多的箱梁桥投入运营,箱梁桥也出现了一些病害,其中梁体混凝土出现各种裂缝问题是比较有代表性的。裂缝的出现不仅影响了桥梁的美观,更重要的是影响了桥梁的安全性和耐久性。本文以陕西境内的两座预应力混凝土连续刚构桥为背景,通过有限元模型计算,对箱梁桥腹板和底板开裂影响因素进行了分析,从设计和构造上提出改进建议。本文主要做了以下工作:(1)首先介绍了箱梁桥的发展概况以及未来的发展趋势;其次介绍了箱梁桥产生的裂缝病害问题,主要介绍箱梁腹板裂缝和底板裂缝;查阅资料,了解国内外学者对于箱梁开裂问题所做的研究和取得的研究成果,以及目前仍存在的问题。(2)介绍了箱梁的挠曲、扭转、畸变和剪力滞效应等空间力学特性和箱梁桥的分析方法,更加清楚地认识箱梁桥的力学行为,为分析提供依据。(3)以实际工程为依托,对箱梁腹板的开裂影响因素进行分析,分析内容包括竖向预应力作用、腹板下弯束的设置及腹板厚度形式的选取对箱梁腹板应力的影响,并提出一些改进建议。(4)以实际工程为依托,对箱梁底板(以跨中梁段为例)的开裂影响因素进行分析,分析内容包括底板合龙束的横向布置形式、底板抛物线次数、箱梁底板厚度及设置横隔板对箱梁底板应力的影响,在分析的基础上提出一些改进建议。
[Abstract]:Prestressed concrete box girder bridge has become the first choice for many bridges because of its strong integrity, large torsional stiffness and many modern construction methods. But with more and more box-girder bridges put into operation, there are some diseases in box-girder bridges. The appearance of cracks not only affects the aesthetics of bridges, but also affects the safety and durability of bridges. Based on two prestressed concrete continuous rigid frame bridges in Shaanxi province, this paper analyzes the influence factors of box girder bridge web and bottom cracking by finite element model calculation, and puts forward some suggestions for improvement in design and construction. The main work of this paper is as follows: firstly, it introduces the development of box girder bridge and the development trend in the future; secondly, it introduces the crack disease of box girder bridge, mainly introduces box girder web crack and bottom plate crack; This paper introduces the spatial mechanical properties of box girder, such as deflection, torsion, distortion and shear lag effect, and the analysis method of box girder bridge. Understand the mechanical behavior of box girder bridge more clearly, provide the basis for analysis. Based on actual engineering, analyze the influencing factors of box girder web cracking, including vertical prestressing force. The influence of the setting of the lower web bending bundle and the selection of the thickness of the web plate on the stress of the web plate of the box girder is put forward, and some improvement suggestions are put forward. Based on the actual project, the factors affecting the cracking of the bottom plate of the box girder (taking the middle span girder section as an example) are analyzed. The contents of the analysis include the transverse arrangement form of the bottom plate, the number of parabola, the thickness of the bottom plate of the box girder and the influence of the setting of the transverse diaphragm on the stress of the bottom plate of the box girder. Based on the analysis, some suggestions for improvement are put forward.
【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】：U441;U445.7

【参考文献】