纵向预应力引起悬浇混凝土箱梁损伤分析及防治措施研究

发布时间：2018-04-08 14:27

本文选题：预应力混凝土箱梁　切入点：结构损伤　出处：《长安大学》2014年硕士论文

【摘要】：预应力混凝土箱形梁以其价廉、美观、抗弯扭性能好等优点在桥梁工程中得到广泛应用，在对已建成的桥梁进行普查中，我国大多数桥梁都不同程度的出现过(主梁跨中位置下挠，跨中正弯矩断面出现下缘裂缝等)病害，造成了重大的经济损失和不利的社会影响，其中由预应力引起箱梁开裂的比例也较高，为此，本文针对纵向预应力引起悬浇混凝土箱梁损伤及防治措施展开研究。首先，介绍了利用杆系计算软件桥梁博士和精细化计算软件MIDAS FEA等分析箱梁损伤的方法以及箱梁损伤检测方法。在箱梁分析中整体计算采用杆系有限元模型，局部分析采用实体有限元模型。通过采用强大的有限元模型进行箱梁分析，使得理论计算结果趋于精准化。在混凝土箱梁施工过程中进行损伤检测，可以获得箱梁内部力学响应即实测值。通过理论值和实测值对比，可以直观明了的了解箱梁内部力学响应。其次，研究了纵向预应力引起腹板混凝土损伤的原因及防治措施，选择一座案例桥进行分析研究。调查箱梁腹板混凝土损伤结果，并对损伤的发展过程进行数值模拟，得到引起损伤的敏感性参数及主要原因，并提出针对性的腹板损伤防治措施。然后，研究了纵向预应力引起底板混凝土损伤的原因及防治措施，结合一座案例桥进行分析研究。调查箱梁底板混凝土损伤形式，并对设计方案和施工过程进行数值模拟，得到引起损伤的敏感性参数及主要原因，并提出针对性的底板损伤防治措施。最后，根据研究成果，在东吴大桥进行成果运用。总之，本文研究纵向预应力引起悬浇混凝土箱梁损伤的机理，并提出防治措施和建议，可有效解决悬浇混凝土箱梁损伤的典型病害问题，对保障桥梁结构的安全，，延长桥梁的使用寿命，降低养护、维修、加固费用，具有重要的意义。
[Abstract]:Prestressed concrete box girder has been widely used in bridge engineering with its advantages of low price, beautiful appearance and good flexural and torsional properties.Most bridges in our country have been damaged to some extent (the main beam deflection in the middle position and the lower edge crack in the middle moment section of the span), which has caused great economic loss and adverse social impact.The cracking rate of box girder caused by prestress is also high. Therefore, the damage caused by longitudinal prestress and the preventive measures are studied in this paper.Firstly, the methods to analyze the damage of box girder and the damage detection method of box girder are introduced, such as the bridge calculation software doctor and the refined calculation software MIDAS FEA.In the box girder analysis, the whole calculation adopts the finite element model of the bar system, and the local analysis adopts the solid finite element model.By using a powerful finite element model for box girder analysis, the theoretical results tend to be accurate.In the process of concrete box girder construction damage detection can obtain the internal mechanical response of box girder that is the measured value.By comparing the theoretical value with the measured value, the internal mechanical response of box girder can be understood intuitively and clearly.Secondly, the causes of web concrete damage caused by longitudinal prestress and the prevention measures are studied, and a case bridge is selected to analyze and study.The damage results of box girder web concrete were investigated and the damage development process was simulated numerically. The sensitive parameters and main causes of the damage were obtained and the corresponding measures for preventing and treating web damage were put forward.Then, the causes and prevention measures of concrete damage caused by longitudinal prestress are studied, and a case study is carried out.The concrete damage form of bottom slab of box girder is investigated, and the design scheme and construction process are numerically simulated. The sensitive parameters and main causes of the damage are obtained, and the corresponding measures to prevent and cure the damage of bottom slab are put forward.Finally, according to the research results, the results are applied in Soochow Bridge.In a word, this paper studies the mechanism of damage caused by longitudinal prestressed concrete box girder, and puts forward some preventive measures and suggestions, which can effectively solve the problem of typical damage of suspended concrete box girder and ensure the safety of bridge structure.It is of great significance to prolong the service life of bridges and reduce the maintenance, repair and reinforcement costs.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.7

【参考文献】