连续钢桁架桥加固方案模糊层次优选及计算分析

发布时间：2018-01-22 14:06

本文关键词： 管道桥钢桁架桥加固模糊优选层次分析法有限元计算　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：从建国至1970年前后，我国自主修建了钢桥，其中运营超过50年的就有1万多孔，他们在我国重要的铁路和交通线上正承担着日益繁重的运输任务。然而随着交通运输事业的发展，交通运输量大幅度增大，再加上常见病害的影响，现有钢桥中有相当一部分不满足使用上的要求，因此对危旧钢桥加固或补强具有现实意义。近些年随着工程结构加固方式、加固材料的多样化，，结构加固方式选择己经不再具有固定可循的方式，在综合考虑经济、技术、结构响应等问题的基础上，模糊综合评价方法和层次分析法在结构加固中的应用己经越来越深入。本文以石化厂黄河管道桥为背景，基于模糊层次优选原理，进行了加固方案优选及计算分析，主要工作如下：（1）阐述了国内外钢桁架桥的发展情况，国内外钢结构加固研究现状，分析我国钢桁架桥加固的必要性。介绍了层次分析法在桥梁加固方案比选中的应用情况，提出桥梁检测-病害总结-层次分析-模糊评判-仿真技术的桥梁加固方案。（2）描述了栓焊钢桁架桥主要病害为：锈蚀、疲劳开裂、变形。总结了钢桁架桥可以采用的维修加固途径，即加固薄弱构件、改变体系、减轻荷载。（3）介绍了加固方案的优选原理。以模糊综合评价法及层次分析法基本理论为基础，根据桥梁加固方案优化选择研究的目的，确定评价方案第一层指标（技术可行、效果可靠、经济合理、施工便利）。（4）结合石化厂黄河管道桥受力机理、病害特点，以及加固方案选择的力学准则、经济指标等提出三层次模糊优选模型及底层评价指标，形成桥梁加固方案三层指标评价模型树。结合桥梁现有病害提出局部构件进行补强，增加新主桁，斜拉方案3套加固方案，并运用模糊层次原理依次确定各层级评价因素的权重，最后对加固方案进行评价，得出新增主桁方案最优。（5）运用有限元对加固前，加固后的桥梁进行受力分析，验证了这套加固方案优选办法在石化厂黄河管道桥优选中具有切实的可行性与实用性。
[Abstract]:From the founding of the people's Republic of China to 1970, our country built the steel bridge on its own, among which more than 50 years of operation has 10,000 holes. They are undertaking more and more heavy transportation tasks on the important railway and traffic lines in our country. However, with the development of transportation, the traffic volume increases greatly, and the influence of common diseases is added. Some of the existing steel bridges do not meet the requirements of use, so it is of practical significance to reinforce or strengthen the old steel bridges. In recent years, with the diversification of structural strengthening methods and strengthening materials, the choice of structural reinforcement methods is no longer fixed, on the basis of comprehensive consideration of economic, technical, structural response and other issues. The application of fuzzy comprehensive evaluation method and analytic hierarchy process (AHP) in structural strengthening has become more and more thorough. On the background of Yellow River pipeline bridge in Petrochemical Plant, based on the principle of fuzzy hierarchical optimal selection, the reinforcement scheme is selected and calculated and analyzed. The main work is as follows: 1) the development of steel truss bridges at home and abroad and the present situation of steel structure reinforcement at home and abroad are expounded. This paper analyzes the necessity of strengthening steel truss bridges in China and introduces the application of AHP in bridge reinforcement scheme selection. A bridge reinforcement scheme based on bridge detection, disease summarization, hierarchical analysis, fuzzy evaluation and simulation is proposed. This paper describes the main diseases of steel truss bridge with bolted welding: rust, fatigue cracking and deformation, and summarizes the ways to repair and reinforce the steel truss bridge, that is, to strengthen the weak members, to change the system and to reduce the load. Based on the fuzzy comprehensive evaluation method and the basic theory of Analytic hierarchy process (AHP), the purpose of the research on the optimal selection of the bridge reinforcement scheme is introduced. Determine the first level index of evaluation scheme (technical feasibility, reliable effect, reasonable economy, convenient construction. Combined with the mechanical mechanism of the Yellow River pipeline bridge in petrochemical plant, the characteristics of the disease, as well as the mechanical criteria for the selection of reinforcement schemes and economic indicators, the three-level fuzzy optimal selection model and the evaluation index for the bottom layer are put forward. Three layer evaluation model tree of bridge reinforcement scheme is formed. Combined with the existing disease of bridge, three sets of reinforcement schemes are put forward to strengthen local members, add new main truss and cable-stayed scheme. The fuzzy hierarchy principle is used to determine the weight of the evaluation factors in turn. Finally, the reinforcement scheme is evaluated and the new main truss scheme is obtained. 5) the finite element method is used to analyze the stress of the bridge before and after reinforcement, which proves the feasibility and practicability of the optimal selection method for the Yellow River pipeline bridge in Petrochemical Plant.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.72

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