曲线钢箱梁桥的顶推（拖拉）监控研究

发布时间：2018-11-26 17:16

【摘要】：随着桥梁施工技术的不断发展,桥梁施工工艺也在不断的更新。顶推法施工对桥位处的交通不会产生太大的影响;和其他施工方式相比需要的施工设备相对而言少;有利于生产组织,可以缩短施工工期。基于这些优点顶推法施工越来越多的被运用到桥梁架设中。但是顶推法施工过程中,桥梁整体的体系转换频繁。随着顶推作业的进行结构的坐标,位移以及受力状态都在不断的发生变化,使得施工过程中结构受力比其他施工方式要复杂。本文以仙岳路-成功大道立交工程主线桥的顶推施工为背景,主要的工作如下:(1)简单介绍了顶推方法起源和顶推法施工的构造;对顶推的方法和原理进行了总结;详细说明了其顶推施工监控系统的建立。(2)运用大型通用有限元软件ANSYS对钢箱梁顶推施工的各个工况逐个建立三维仿真模型,根据基本工程资料,确定相关模型参数、选取合理的单元。对不同的工况进行模拟顶推施工,确定施工过程中需要控制的参量。(3)针对顶推(拖拉)过程导梁从最大悬臂状态至跨过成功大道时,导梁从最大负弯矩状态变换为最大正弯矩状态,工字钢导梁上下翼缘板均有发生局部失稳的现状,建立了导梁精细化有限元模型,对导梁的截面形式提出了优化建议、并对工字钢导梁上下均设置了局部加劲肋,顶对过程在导梁关键部位布置了传感器,理论分析计算结构与现场实测相互应证,保证了导梁结构的安全运行。(4)对实际顶推施工中的位移,应变进行实测。在对应的工况下与有限元模型计算值进行对比,实时调整模型参量,指导下一个施工工况。(5)针对顶推(拖拉)过程各个支撑滑块支撑反力不断变化、且有可能发生三点支撑的现实情况,通过建立底板、腹板区域精细化有限元模型仿真分析,得到底板与腹板交接区域通过滑块是局部应力很大极有可能发生局部失稳的情况,建议对该区域增设纵、横向局部加劲肋,并在改区域布置了传感器,顶推(拖拉)过程应力传感器实测数据应证了局部精细有限元仿真结果的正确性,所提出的增设局部加劲肋的建议保证了钢箱梁底板通过滑块时的安全,避免了钢箱梁局部失稳损伤事故的发生,是钢箱梁顺利实现顶推(拖拉)的重要技术保障措施。(6)顶推(拖拉)全过程不仅对钢箱梁总体位移进行检测、而且对报告支撑墩在内的附属结构进行全程安全性监测,实施对有限元计算结果于施工实测结果进行对比分析,一旦发生较大偏差立即分析原因,从而保证了整个桥梁顶推施工的安全。本文研究方法与所得结论可为同类桥梁施工提供参考。
[Abstract]:With the continuous development of bridge construction technology, bridge construction technology is constantly updated. Compared with other construction methods, the construction equipment needs less, is advantageous to the production organization, and can shorten the construction period. Based on these advantages, more and more construction methods are used in bridge erection. However, in the construction process of the jacking method, the system transformation of the whole bridge is frequent. With the continuous change of the coordinate displacement and stress state of the structure during the construction process the structural force is more complicated than other construction methods. The main work of this paper is as follows: (1) the origin of the thrusting method and the construction of the jacking method are briefly introduced, and the methods and principles of the thrusting are summarized. The establishment of monitoring system for jacking construction is explained in detail. (2) the 3D simulation model of steel box girder jacking construction is established one by using the large-scale universal finite element software ANSYS, and the relevant model parameters are determined according to the basic engineering data. Select reasonable units. The parameters to be controlled in the construction process are determined by simulating the jacking construction under different working conditions. (3) when the guide beam is in the state of maximum cantilever from the maximum cantilever state to the crossing of the main road of success in the process of pushing (towing), The guide beam is transformed from the maximum negative moment state to the maximum positive moment state, and the local instability occurs in the upper and lower flange plates of the guide beam of I-beam. The finite-element model of the guide beam is established, and the optimization suggestions for the section form of the guide beam are put forward. A local stiffening rib is set up for the I-beam guide beam up and down, and the top pair is arranged in the key part of the guide beam. The theoretical analysis and calculation structure and the field measurement verify each other. The safety operation of the guide beam structure is ensured. (4) the displacement and strain in the actual jacking construction are measured. The model parameters are adjusted in real time to guide the next construction condition. (5) the support reaction force of each support slider is constantly changing in the process of pushing (dragging). And it is possible to have the reality of three-point support. Through the simulation analysis of the finite-element model of the bottom plate and the web region, it is concluded that the local stress of the interface area between the bottom plate and the web through the sliding block is very large and the local instability is likely to occur. It is suggested that longitudinal and lateral local stiffeners should be added to the region, and sensors are arranged in the modified area. The measured data of the stress sensors during the push-pull process should prove the correctness of the local fine finite element simulation results. The suggestion of adding local stiffener ensures the safety of the steel box girder bottom plate when it passes through the slider, and avoids the occurrence of the local instability damage accident of the steel box girder. It is an important technical guarantee measure for the steel box girder to smoothly realize the pushing (towing). (6) the whole process of pushing (towing) not only detects the total displacement of the steel box girder, but also monitors the safety of the auxiliary structure, including the report supporting pier, in the whole process. The results of finite element calculation are compared with the measured results of construction, and the reasons are analyzed immediately once a large deviation occurs, thus ensuring the safety of the whole bridge jacking and pushing construction. The research method and conclusion of this paper can provide reference for the similar bridge construction.
【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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