基于日常检测的空心板梁桥的安全评估体系

发布时间：2018-04-11 09:23

本文选题：空心板 + 铰缝损伤　；参考：《重庆交通大学》2015年硕士论文

【摘要】：随着经济的发展,我国高速公路上的桥梁也越来越多。有些桥梁虽然还未超过服役年限,但却因为超载等因素的影响使得其设计承载力已不符合现在的使用要求。而新建的桥梁也会因为设计或施工上的缺陷而发生损伤,这些损伤都不同程度上威胁了桥梁的安全。空心板桥梁由于其结构简单、适合标准化施工、施工方便等优点而在公路桥梁被广泛采用。由于空心板梁桥所占有的比重较大,出现的安全问题也相对较多。在上述背景下,本论文以空心板梁桥作为研究对象,针对其安全性评估问题展开研究,主要研究内容包括:①首先对空心板梁桥常见病害进行归类分析,详细介绍了空心板梁桥具有代表性和普遍性的病害。②以跨径为10m的普通钢筋混凝土空心板梁桥及13m、20m的预应力混凝土空心板梁桥为原型,建立无损伤铰缝、单个铰缝损伤、相邻两个铰缝损伤的Midas Fea有限元模型,分别模拟铰缝损伤20%、40%、60%以及80%的情况。通过分析不同损伤程度下的挠度横向分布系数,确定铰缝损伤对空心板梁桥安全性能的影响。③通过Midas Fea建立反映结构真实状态的10m普通钢筋混凝土以及20m预应力混凝土空心板梁桥有限元模型。以裂缝高度为研究参数,进行了单调加载和反复加载下的非线性有限元分析,研究空心板梁桥不同裂缝状态下的内力和变形情况,最终构建空心板梁桥的基于裂缝开展程度的安全性评估技术。另外还对预应力空心板梁桥模型的梁端纵向小裂缝进行了分析,对其产生原因进行了进一步的分析。④将主梁受压区混凝土应变达到极限应变作为前提,运用数学计算分析手段,通过各项确定因素的分析,建立了运用简便的空心板梁桥永久性变形限值公式。然后通过Midas Civil分别建立跨径为13m、16m、20m的预应力混凝土空心板梁桥有限元模型,研究由于预应力损失引起的下挠对空心板梁桥的影响。通过限值公式和有限元模拟结果的比较分析可知,永久性变形理论限值公式可以用于空心板梁桥安全性能的评定。论文的研究成果为客观评价空心板桥的安全性提供了较好的理论和实践依据,对保证空心板梁桥的安全具有积极的现实意义,推广应用前景良好。
[Abstract]:With the development of economy, there are more and more bridges on highway in our country.Although some bridges have not exceeded their service life, the design bearing capacity of some bridges does not meet the current requirements due to the influence of overload and other factors.New bridges will also be damaged by defects in design or construction, which in varying degrees threaten the safety of bridges.Hollow slab bridges are widely used in highway bridges because of their simple structure, suitable for standardized construction and convenient construction.Because of the large proportion of hollow slab girder bridge, there are many safety problems.Under the above background, this paper takes the hollow slab girder bridge as the research object, aiming at its safety evaluation problem, the main research content includes: firstly, the common diseases of the hollow slab girder bridge are classified and analyzed.It is introduced in detail that the typical and universal disease of hollow slab girder bridge is that the common reinforced concrete hollow slab girder bridge with span of 10 m and prestressed concrete hollow slab beam bridge with 13 m or 20 m span are used as archetypes to establish the joint without damage and single joint damage.The Midas Fea finite element model for the damage of two adjacent joints is used to simulate the damage of the hinge joints by 60% and 80% respectively.By analyzing the transverse distribution coefficient of deflection under different damage degree,The influence of hinged joint damage on the safety performance of hollow slab girder bridge was determined. 3 the finite element models of 10 m ordinary reinforced concrete and 20 m prestressed concrete hollow slab girder bridge reflecting the real state of the structure were established by Midas Fea.Finally, the construction of hollow slab girder bridge based on crack development degree of safety assessment technology.In addition, the longitudinal small cracks at the beam end of the prestressed hollow slab bridge model are analyzed, and the causes are further analyzed. 4. The ultimate strain of concrete in the compression zone of the main beam is taken as the prerequisite.By means of mathematical calculation and analysis, a simple and convenient formula of permanent deformation limit of hollow slab girder bridge is established through the analysis of certain factors.By comparing the finite value formula with the finite element simulation results, it can be seen that the permanent deformation theory limit formula can be used to evaluate the safety performance of hollow slab girder bridge.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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