箱型刚构桥水平转体施工监控及应力与挠度影响因素的研究

发布时间：2018-01-16 03:19

本文关键词：箱型刚构桥水平转体施工监控及应力与挠度影响因素的研究　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：科技的进步,国民经济的健康飞速发展促使了我国交通业能力的不断进步,桥梁作为交通领域必不可少的重要组成部分,正在发挥着越来越大的作用。但是,近年来在桥梁工程的修建中常遇到将要修建的新工程要跨越正常运营而且运输任务繁忙的既有线路,但这种线路的中断或发生事故将会产生较大的经济损失甚至有生命危险。像这种受到交通限制或地形的影响,普通桥梁施工工艺满足不了得时候,桥梁转体施工技术诞生了。经过桥梁专家和工程师长时间的不断探索,桥梁转体施工技术理论不断走向成熟,成功运用到了一座又一座实际工程。桥梁转体施工在发挥了自身独特的优势的同时,带来了巨大的社会经济效益,因此将会在未来的工程和科研领域具有较大实用优势和较广阔的发展空间。本文以凌源至绥中高速公路建昌至兴城支线丁家沟公铁分离式立交桥(80m+80m)预应力混凝土刚构桥的实际工程为研究对象,研究了该桥的施工过程中各阶段的力学性能,对该桥做了详细的监控方案和部分技术支持,并通过对该桥的模拟和数据分析得到了影响刚构桥的应力和长期挠度的主要因素。本文做的工作主要从以下方面展开研究:首先,运用桥梁有限元软件MIDAS CIVIL对结构的施工过程进行了仿真模拟,通过施工过程中采集的数据及时与真实值作比较,不断调整和拟合,确保梁体达到较好的受力性能以及梁体的挠度和应力变化在有效的控制之中,为本桥的顺利转体与精确合拢增加了保障。其次,由数据对比和模型建立分析了影响连续刚构桥应力及梁体长期挠度主要因素。分析发现温度效应对梁体应力的影响较大,但在控制范围之内。梁体混凝土的收缩徐变和预应力损失对结构的长期挠度影响很大,尤其相对湿度的变化和预应力张拉控制应力的折减分别对混凝土收缩徐变和预应力损失影响显著。接着分析了刚度损失、超重和预应力钢筋应力松弛对结构长期挠度的影响,发现其影响都不大,但在施工中却不可以忽略。最后总结了本文得出的结论并对今后刚构桥的转体施工与设计提出改进意见。
[Abstract]:With the development of science and technology and the healthy and rapid development of national economy, the capacity of our country's transportation industry has been improved continuously. As an essential part of the transportation field, bridge is playing a more and more important role. In recent years, in the construction of bridge engineering, it is often encountered that the new project to be built will cross the existing lines which have normal operation and heavy transportation tasks. However, the interruption or accident of this kind of line will cause great economic loss and even life danger. For example, due to traffic restrictions or terrain, ordinary bridge construction technology can not meet the time. The bridge rotation construction technology was born. After a long time of continuous exploration by bridge experts and engineers, the theory of bridge rotation construction technology continues to mature. It has been successfully applied to one actual project after another. The bridge rotation construction has brought great social and economic benefits while giving play to its own unique advantages. Therefore, it will have great practical advantages and broad development space in the future engineering and scientific research field. This paper uses the separated railway overpass of Lingyuan-Suizhong Expressway from Jianchang to Xingcheng spur Line (. 80m 80m) the actual project of prestressed concrete rigid frame bridge is the research object. The mechanical properties of the bridge during the construction process are studied, and the detailed monitoring scheme and some technical support are given. Through the simulation and data analysis of the bridge, the main factors affecting the stress and long-term deflection of the rigid frame bridge are obtained. The work of this paper is mainly carried out from the following aspects: first. The bridge finite element software MIDAS CIVIL is used to simulate the construction process of the structure. The data collected during the construction is compared with the real value in time, and it is constantly adjusted and fitted. Ensure that the beam to achieve better mechanical performance and beam deflection and stress changes in the effective control for the smooth rotation and accurate closure of the bridge increased the protection. The main factors that influence the stress of continuous rigid frame bridge and the long-term deflection of beam body are analyzed by comparing the data and modeling. It is found that the temperature effect has a great effect on the stress of beam body. However, within the scope of control, the shrinkage and creep of beam concrete and the loss of prestress have great influence on the long-term deflection of the structure. Especially the change of relative humidity and the reduction of prestressed tensioning control stress have significant influence on shrinkage creep and prestress loss of concrete respectively. Then the stiffness loss is analyzed. The influence of stress relaxation of overweight and prestressed steel bar on the long-term deflection of the structure is found to be small. In the end, the conclusion of this paper is summarized and some suggestions for improving the construction and design of the rigid frame bridge in the future are put forward.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4

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