大跨度连续梁—钢桁架组合结构桥施工监控研究与实践

发布时间：2018-06-22 04:57

本文选题：连续梁-钢桁架组合结构 + 仿真分析　；参考：《重庆大学》2014年硕士论文

【摘要】：连续梁-钢桁架组合结构桥作为一种新型的桥梁结构形式，不仅能够有效降低下部混凝土箱梁高度，提升桥梁整体刚度，还具有良好的动力特性。国内外对该种新型桥梁结构形式的研究工作仍处于起步阶段，有不少问题值得研究。本文以目前国内最大跨度(主跨为168m)的连续梁-钢桁架组合结构桥-跨兰西高速公路特大桥为工程背景，主要进行了以下内容研究： ①确定了连续梁-钢桁架组合结构桥的施工控制内容，介绍了施工过程的分析方法，同时对混凝土收缩徐变模式的选取进行了较为深入的研究，并根据现场实际情况建立了一套较为完整的监控系统。 ②建立了连续梁-钢桁架组合结构的有限元模型，分析了施工过程中主梁结构的线型变化和应力分布规律，并用MIDAS和CSB的计算结果进行对比分析，验证了计算结果的可靠性。 ③以MIDAS有限元模型为基础，，进行了混凝土容重、混凝土弹性模量、预应力、以及环境温度参数偏差对主梁线型和应力的影响分析。并根据分析结果在施工现场采取了相应的措施对结构的线型和应力控制变量进行修正。 ④针对跨兰西高速公路特大桥的线型控制，进行了高程测点的布设、观测及理论立模标高值的修正，提出了合理考虑各种因素的立模标高的确定方法。同时，确定了该桥下节点板的预埋精度的控制方法和钢桁架拼装的合理方案，保证了后期钢桁架的合拢精度。 ⑤进行了该桥施工过程中主梁关键截面的应力控制，确保了施工过程中结构的安全。同时，对主梁2#块截面进行了剪力滞效应分析，并与实测数据进行了对比分析，分析表明在悬臂施工过程中2#块截面表现为正剪力滞现象，顶、底板腹板处剪力滞系数为1.1-1.4，不会出现局部应力过大现象。
[Abstract]:As a new type of bridge structure, continuous beam-steel truss composite structure bridge can not only effectively reduce the height of the lower concrete box girder, enhance the overall stiffness of the bridge, but also have good dynamic characteristics. At home and abroad, the research on this new type of bridge structure is still in its infancy, and there are many problems worth studying. In this paper, the project background is the continuous beam-steel truss composite structure bridge with the largest span (the main span is 168m). The main contents are as follows: 1 the construction control content of continuous beam-steel truss composite structure bridge is determined, and the analysis method of construction process is introduced. At the same time, the selection of shrinkage and creep mode of concrete is studied deeply, and a set of complete monitoring system is established according to the actual situation in the field. 2 the finite element model of continuous beam-steel truss composite structure is established. This paper analyzes the linear variation and stress distribution of the main beam structure during construction, compares and analyzes the calculation results of Midas and CSB, and verifies the reliability of the calculation results. 3 based on the Midas finite element model, the reliability of the calculation results is verified. The influence of concrete bulk density, concrete elastic modulus, prestress and ambient temperature parameter deviation on the main beam alignment and stress is analyzed. According to the results of the analysis, the corresponding measures are taken to modify the structural alignment and stress control variables in the construction site. 4 according to the alignment control of the super bridge of the Trans-Lanxi Expressway, the elevation survey points are arranged. Based on the observation and the correction of the theoretical elevation, a method for determining the elevation of the vertical model is put forward, which considers all kinds of factors reasonably. At the same time, the control method of the embedded precision of the joint plate under the bridge and the reasonable scheme of assembling the steel truss are determined to ensure the closing accuracy of the steel truss in the later stage. 5 the stress control of the key section of the main beam during the construction of the bridge is carried out. It ensures the safety of the structure during the construction process. At the same time, the shear lag effect of the beam block section is analyzed and compared with the measured data. The analysis shows that the section of the beam block is a positive shear lag phenomenon in the cantilever construction process. The shear lag coefficient at the bottom web is 1.1-1.4, and the local stress is not excessive.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4;U446

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