跨铁路线预应力混凝土连续箱梁桥顶推施工关键问题分析

发布时间：2018-04-02 19:38

本文选题：混凝土连续梁桥　切入点：顶推施工　出处：《长沙理工大学》2014年硕士论文

【摘要】：预应力混凝土连续梁桥由于其结构刚度好、少伸缩缝、变形小、易养护、经济适用等优点在桥梁建设中占有不可或缺的地位。在桥梁施工过程中,常受到地形、地貌、交通运输线路等条件的限制,而顶推施工方法具有经济、必要设备少、所需施工场地小等优点,因而在桥梁施工中得到了广泛的应用。本文以顶推法施工的跨铁路线预应力混凝土连续箱梁桥为研究对象,围绕湘府路湘江大桥京广跨线联这一工程背景,对顶推施工中的仿真分析、主墩与临时墩的承载能力、钢导梁试验以及顶推过程中的施工控制等展开研究。本文主要工作如下：(1)通过对连续梁桥顶推施工仿真计算的两种基本形式(梁动墩不动模型和墩动梁不动模型)的对比分析,根据工程背景的相关情况选取墩动梁不动模型形式来进行相关计算分析。应用Midas Civil软件对该桥顶推施工全过程进行仿真计算分析,然后针对顶推施工过程中主墩的最不利情况对其进行承载能力的验算、并在采取加固措施后进行再次复核,得到的结果满足要求；(2)通过建立的该桥顶推施工全过程的仿真计算分析模型,得到钢导梁在顶推过程中在导梁与主梁联结处的最大弯矩的最不利工况,并确定钢导梁试验方案。然后针对钢导梁试验实施过程中主梁与导梁连接处梁体出现裂缝的现象,建立该联的空间实体模型,分析顶推过程中最不利工况下的结构受力情况,探讨钢导梁试验重要性,以及相关分析。模型计算结果与现场实施过程中出现的问题相一致,计算得到在梁体出现裂缝位置处(即主梁与导梁联结处腹板的下部)存在有较大拉应力；(3)结合工程实例中顶推过程施工控制的横向偏位、应力、挠度、裂缝等方面的监测进行分析,为以后同类型桥梁顶推施工控制留下可靠的借鉴经验。
[Abstract]:Prestressed concrete continuous beam bridge plays an indispensable role in bridge construction because of its advantages such as good structural stiffness, less expansion joints, small deformation, easy maintenance, economic applicability and so on.In the process of bridge construction, it is often restricted by the conditions of topography, geomorphology, transportation line, etc. However, the method of pushing construction has the advantages of economy, few necessary equipment and small construction site, so it has been widely used in bridge construction.In this paper, the prestressed concrete continuous box girder bridge constructed by the pushing method is taken as the research object, and the simulation analysis, the bearing capacity of the main pier and the temporary pier are analyzed around the engineering background of the Beijing-Guangzhou cross-line connection of Xiangjiang Bridge on the Xiangjiang River, Xiangfu Road, Xiangjiang River, Xiangjiang River, Xiangjiang River, Xiangjiang River, Hunan Province, Hunan Province.The test of steel guide beam and the construction control in the process of pushing are studied.The main work of this paper is as follows: (1) by comparing and analyzing the two basic forms of simulation calculation of continuous beam bridge's jacking construction (beam moving-pier immobility model and pier moving-beam immobility model),According to the relevant situation of engineering background, the fixed model form of pier moving beam is selected to carry on correlation calculation and analysis.Midas Civil software is used to simulate and analyze the whole process of jacking and construction of the bridge, and then the bearing capacity of the main pier is checked according to the most disadvantageous condition of the main pier in the process of jacking construction, and the reinforcement measures are taken to recheck the load capacity of the main pier.The obtained results meet the requirements of the bridge. By establishing the simulation analysis model of the whole process of the jacking and construction of the bridge, the most unfavorable working conditions of the maximum bending moment of the steel guide beam at the junction between the guide beam and the main beam during the jacking and pushing process are obtained, and the test scheme of the steel guide beam is determined.Then, in view of the cracks in the beam body at the connection between the main beam and the guide beam during the steel guide beam test, the spatial solid model of the joint is established, and the stress situation of the structure under the most unfavorable working conditions during the pushing process is analyzed, and the importance of the steel guide beam test is discussed.And related analysis.The results of the model are consistent with the problems in the field implementation.The calculation results show that there is a large tensile stress at the crack position (that is, the lower part of the web at the junction between the main beam and the guide beam) and the lateral deflection, stress and deflection controlled by the construction control in the pushing process in the engineering example.The monitoring of cracks and other aspects are analyzed in order to leave reliable experience for the construction control of the same type of bridges in the future.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.462

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