超高性能混凝土对轻型组合桥面结构疲劳寿命的影响研究

发布时间：2018-01-06 21:08

本文关键词：超高性能混凝土对轻型组合桥面结构疲劳寿命的影响研究　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：正交异性钢桥面板具有重量轻、承载能力高、施工快、整体性强等优点，现已广泛应用于世界各国大跨径钢桥中。然而，大量的工程实践表明，正交异性钢桥面板存在两大技术难题：钢结构疲劳开裂和铺装层损坏。国内外研究人员通过几十年的探索，进行了很多有益的尝试，但仍未能从根本上解决上述难题。为此，笔者所在的研究团队提出将具有高弹性模量、高抗拉强度的配筋超高性能混凝土(Ultra-High Performance Concrete，简称UHPC)引入正交异性钢桥面板中，形成“轻型组合桥面板结构”，以期解决上述两种病害。本文基于虎门悬索桥桥面改造工程，对“轻型组合桥面结构”的疲劳性能进行了研究，主要完成了以下工作：（1）综述了传统钢桥面的使用现状、病害及病害原因，对UHPC材料性能进行介绍，并引入轻型组合桥面结构的概念。（2）系统全面地综述了钢桥疲劳理论：钢桥抗疲劳设计方法、钢桥疲劳寿命评估S-N曲线、钢桥疲劳验算方法等。阐明了钢桥面的三大基本体系。（3）利用ANSYS有限元软件建立了虎门悬索桥钢箱梁局部梁段疲劳分析模型。利用热点应力法，分别对0mm、45mm、60mm厚度UHPC层情形，钢桥面常见焊接和非焊接易疲劳开裂细节，进行应力幅计算。并对采用45mm厚度UHPC层的轻型组合桥面板进行了疲劳寿命评估。分析结果表明：轻型组合桥面板中UHPC层对于面板与纵肋连接细节与纵肋对接细节，应力幅改善作用很大，而对其余细节，其改善程度相对较小。采用45mm厚UHPC层时，中车道累计通过8,035,868辆330kN标准疲劳车后，横隔板与U肋相交处将出现隔板疲劳开裂现象。（4）基于虎门大桥桥面板条带足尺模型，设计并开展静载破坏试验与疲劳试验。静载试验表明：UHPC材料在开裂后具有应变强化现象，并且表现出很长一段延性；在受拉线弹性设计中，其弹性模量建议取值40.1GPa。疲劳试验结果表明：在UHPC层应力幅为9.8MPa~24.3MPa的疲劳荷载作用下，历经3,101,389次疲劳循环，UHPC层表面未见可视裂缝，，按疲劳极限等效理论换算，此应力幅相当于0.0MPa~21.3MPa，因而UHPC的抗弯拉疲劳强度折减系数大于0.5，完全能满足虎门大桥UHPC层的抗弯拉疲劳强度要求。
[Abstract]:The orthotropic steel deck has the advantages of light weight, high capacity, fast construction, has the advantages of strong integrity, is now widely used in the world of long-span steel bridges. However, a large number of engineering shows that there are two major technical problems of Orthotropic Steel Deck: steel structure fatigue cracking and pavement damage. Researchers at home and abroad by exploration of a few years, have a lot of useful attempts, but still failed to fundamentally solve the above problems. Therefore, our research team proposed has high elastic modulus, high tensile reinforcement strength of ultra high performance concrete (Ultra-High Performance Concrete, referred to as UHPC) the introduction of the orthotropic steel deck, the formation of "light the composite bridge deck structure", in order to solve the above two kinds of diseases.
Based on the reconstruction project of Humen suspension bridge deck, the fatigue performance of "light combined deck structure" is studied, and the following work is completed.
(1) the present situation of the use of the traditional steel bridge surface, the causes of disease and disease, the performance of UHPC materials are introduced, and the concept of light combined deck structure is introduced.
(2) systematically summarized the fatigue theory of steel bridges: the design method of fatigue resistance for steel bridges, the S-N curve for fatigue life evaluation of steel bridges, and the fatigue checking method for steel bridges. The three basic systems of steel bridge deck are clarified.
(3) establish the analysis model of steel box girder of Humen suspension bridge local girder fatigue by using finite element software ANSYS. By using hot spot stress method, respectively for 0mm, 45mm, 60mm, UHPC layer thickness, common welded and non welded steel deck fatigue crack details, the stress amplitude is calculated. And the thickness of 45mm layer UHPC the light composite deck were fatigue life assessment. Analysis results show that the lightweight composite bridge deck in UHPC layer for panels with longitudinal ribs and longitudinal rib butt connection details details, stress amplitude is greatly improved, and the rest of the details, the degree of improvement is relatively small. With 45mm thick UHPC layer, Lane cumulative by 8035868 330kN standard fatigue car, the diaphragm and the U rib intersection will appear diaphragm fatigue cracking phenomenon.
(4) the full-scale model of Humen bridge panel strip based on design and carry out static loading test and fatigue test. The static load test showed that the UHPC material with strain hardening phenomenon after cracking, and showed a long pull in ductility; elastic design, the elastic modulus values of the fatigue test results of 40.1GPa. show that the stress amplitude of 9.8MPa~24.3MPa fatigue loading in the UHPC layer, after 3101389 times of fatigue cycle, the UHPC layer was visible cracks, according to the fatigue limit of the theory of equivalent conversion, the stress amplitude is equivalent to 0.0MPa~21.3MPa, so the flexural fatigue strength of UHPC reduction coefficient is greater than 0.5, can fully meet the Humen bridge UHPC the flexural fatigue strength requirements.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U443.31

【参考文献】