跨铁路PC箱梁桥顶推施工安全监控及关键技术研究

发布时间：2018-04-11 11:40

本文选题：PC箱梁 + 跨铁路　；参考：《西南交通大学》2015年硕士论文

【摘要】：论文以昆明市老320国道升级改造工程之跨沪-昆铁路桥顶推施工为工程背景,对顶推施工过程进行了仿真分析。对主梁、导梁及墩的应力状态开展了研究。同时结合工程中出现的导梁前端下挠位移过大、支反力过大和局部应力过大等问题开展了研究；并探讨了相关影响因素,这些因素主要包括导梁参数、截面温度梯度和支座沉降等。为了避免主梁内力过大,导梁前端能够顺利搭上临时墩,确保箱梁应力处于安全水平,论文主要完成了以下工作：(1)根据现场施工经验,总结了顶推施工中常见的关键问题。(2)根据顶推施工过程,进行有限元仿真分析,研究了顶推施工中主梁、导梁及墩的位移、应力和稳定性；利用闭环控制法和最大宽容度法进行安全监控,并将监测的结果与计算结果进行分析对比,达到了预期效果。(3)研究了导梁的刚度、重量及长度对顶推施工工艺的影响,如主梁的内力和导梁前端位移的变化,并做出总结。研究结果为导梁的设计和优化提供了理论支撑。(4)研究了顶推施工过程中的敏感性参数,如截面温度梯度、支座沉降及边界条件等。考察了对支座支反力、梁体内力和导梁前端位移的变化规律,为同类顶推施工的顺利进行提供了参考。(5)在全桥三维模型基础上,分析了支座脱空后对支反力和箱梁局部应力集中的影响。论文的研究结果,可以为同类工程的设计,施工和养护提供参考。
[Abstract]:In this paper, based on the engineering background of the pushing construction of the railway bridge across Shanghai and Kunming in the upgrading project of the old 320 national highway in Kunming, the simulation analysis of the construction process is carried out.The stress state of main beam, guide beam and pier is studied.At the same time, the problems such as too large deflection displacement at the front end of the guide beam, too large support reaction force and excessive local stress are studied, and the related influencing factors are discussed, which mainly include the parameters of the guide beam.Section temperature gradient and bearing settlement etc.In order to avoid the excessive internal force of the main beam, the front end of the guide beam can be successfully mounted on the temporary pier to ensure that the stress of the box girder is in a safe level, the following work has been accomplished in this paper: 1) according to the field construction experience,According to the process of jacking construction, finite element simulation analysis is carried out, and the displacement, stress and stability of main beam, guide beam and pier in jacking construction are studied.The closed-loop control method and the maximum tolerance method are used to monitor the safety, and the results of monitoring and calculation are analyzed and compared. The expected effect is achieved. The influence of the stiffness, weight and length of the guide beam on the jacking construction technology is studied.For example, the internal force of the main beam and the displacement of the front end of the guide beam are changed and summarized.The research results provide theoretical support for the design and optimization of the guide beam. The sensitive parameters in the process of jacking and pushing are studied, such as the temperature gradient of the section, the settlement of the bearing and the boundary conditions, etc.The variation law of the reaction force of support, the force inside the beam and the front displacement of the guide beam are investigated, which provides a reference for the smooth construction of the similar jacking and pushing construction on the basis of the 3D model of the whole bridge.The effect of support emptying on support reaction force and local stress concentration of box girder is analyzed.The research results can provide reference for the design, construction and maintenance of similar projects.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.462

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