连续梁桥悬臂现浇施工关键技术与控制方法研究

发布时间：2018-01-12 23:10

本文关键词：连续梁桥悬臂现浇施工关键技术与控制方法研究　出处：《东南大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年来随着我国交通事业的迅速发展,桥梁跨径的不断增大,预应力混凝土连续梁桥在桥梁建设中得到了广泛的应用,悬臂现浇施工也成为现代大跨径桥梁建设的主要施工方法。采用悬臂现浇施工的连续梁桥要经历一个复杂的施工过程,过程中不仅要确保桥梁建设进度和质量,也要保证处于动态变化中的结构在成桥后满足线形和受力要求,因此有必要对连续梁桥悬臂现浇施工关键技术和控制方法进行针对性研究。本文以宿扬高速公路白塔河桥为工程背景,首先对连续梁桥悬臂现浇过程中的临时固结技术、挂篮施工技术和合拢段施工技术展开研究,从施工进程角度首先介绍了墩梁临时固结的布置方式,针对墩顶临时固结方式校核精轧螺纹钢的抗压性能、锚固长度和支墩混凝土的承压性能以确保施工过程中的稳定性；其后对悬臂浇筑过程中所使用的挂篮分析其选择机制和结构构造,利用Midas/Civil建立挂篮有限元模型,分析挂篮上横梁、底篮和吊杆的受力性能,介绍了挂篮预压静载试验,并绘制挂篮弹性变形曲线图为后期计算施工预拱度作准备；最后对合拢段临时固结、合拢施工温度和合拢施工配重展开论述。三项重要施工技术在时间进程上涵盖了桥梁建设全周期,为保证桥梁施工质量和进度奠定了基础。结合以上连续梁桥悬臂现浇施工的工艺特点,本文选择正装分析法对白塔河桥主桥施工过程进行模拟。在确定有限元模型的设计参数、计算荷载、边界条件及划分施工工况后,利用MIDAS/Civil建立了白塔河桥的有限元计算模型,进行白塔河桥主桥施工全过程仿真分析,预测并分析了施工过程中梁段受力和变形。在施工过程模拟有限元分析的基础上,针对连续梁桥施工控制过程中可控参数进行了敏感性分析,研究在桥梁建设过程中对结构扰动较大的因素,以便在施工控制中实时修正理论模型和反馈控制,分析结果表明混凝土自重荷载和预应力荷载偏差对桥梁结构在施工阶段和成桥阶段的结构挠度和应力影响较大。由于温度对混凝土结构的受力和变形同样存在一定影响,本文在总结以往箱梁结构温度分布形式的基础上将温度影响划分为体系温差和梯度温差两种温度作用形式,介绍了温度荷载在混凝土内部产生两种温差应力的机理,然后分析两种温差作用对桥梁在施工阶段和成桥阶段线形和应力的影响,为桥梁施工控制中考虑温度效应提供理论依据。基于上述施工控制参数敏感性和温度效应分析结果,选择自适应控制法建立白塔河桥施工控制体系,具体实施白塔河桥的线形控制和应力监控。在线形控制中介绍了立模标高设置原理、全桥高程观测网布置方法和测量方法,并利用灰色系统理论GM(1,1)模型将理想状态和实测状态下的桥面高程差作为灰微分序列建模,预测待施工阶段的偏差并修正立模标高,最后白塔河桥顺利合拢、线形平顺,表明灰色理论预测控制具有较强的适应性和实用性。在应力监控中介绍了应变计的选择及工作原理、应力测点监控网的布置和监测方法,应力监测结果显示实测应力与理论应力保持一致的规律性且误差较小,表明经过自适应控制的参数修正和误差修正,结构理论状态和施工实际状态相似程度较高。
[Abstract]:In recent years, with the rapid development of transportation in our country. The increase of the span prestressed concrete continuous girder bridge is widely used in bridge construction, cantilever cast-in-place construction has become the main construction method of long-span bridge construction. The cantilever cast-in-place continuous beam bridge construction is a complex during the construction process, not only to ensure that the progress of bridge construction and quality, but also to ensure that in the dynamic changes in the structure to meet the requirements of linear and stress in the bridge, so it is necessary for the continuous beam cantilever cast-in-place construction key technology and control method for research. This paper places Yang Expressway Bridge as the engineering tower the background, first on the temporary consolidation technology of continuous beam bridge cantilever cast-in-place process, hanging basket construction technology and construction technology of closure segment construction, from the point of the process first introduced the pier beam Layout of the temporary consolidation, the compressive properties of the pier top way to check temporary consolidation bar, anchorage length and pier bearing performance of concrete to ensure stability in the construction process of the hanging basket; then using the cantilever casting process analysis of the selection mechanism and structure, using Midas/Civil to establish the finite element model of the hanging basket analysis on the beam, hanging basket, basket bottom and suspender force performance, introduces the Cradle preloading static load test, and draw the curve of elastic deformation of the hanging basket for later calculation of the camber of construction preparation; at the end of the closure section of temporary consolidation, closure construction temperature and weight closure construction are discussed. Three the important construction technology covers the full cycle of bridge construction in the course of time, it lays a foundation to guarantee the quality of bridge construction and progress. With the above continuous beam cantilever cast-in-place construction technology characteristics, anthology Choose a formal analysis to simulate the construction process of bridge tower load calculation method. The design parameters, determining the finite element model, boundary conditions and division of construction conditions, using MIDAS/Civil to establish the finite element calculation model of the bridge tower, analyze the simulation of the whole process of Baita river bridge main bridge construction, and analyzes the prediction and deformation of girder construction in the process of stress. Based on Simulation of finite element analysis in the construction process, the controllable construction control of the continuous beam bridge parameter sensitivity analysis, perturbation of larger factors on the structure in the bridge construction process, in order to construction control of real time correction model and feedback control, analysis results show that the concrete gravity load and prestress load deviation of bridge structure during the construction period and the stage of bridge structure deflection and stress influence because of the temperature of the concrete structure. The stress and deformation also has certain effect in the previous box girder structure form based on the temperature distribution of temperature effect is divided into system temperature and gradient temperature difference of two kinds of temperature effect, the temperature load creates two kinds of temperature stress in the concrete mechanism, then analyzes the two kinds of temperature effect on the bridge the construction stage and the bridge alignment and stress effects, temperature effects are considered in the construction control of bridge construction to provide the theory basis. The control parameter sensitivity and temperature effect analysis based on the results of selection of adaptive control method to establish the construction control system of Baita River Bridge, Baita bridge concrete implementation of the linear control and stress monitoring in linear control. The elevation of formwork setting principle, full bridge elevation observation network layout method and measurement method, and using the theory of grey system GM (1,1) model of the ideal state The deck elevation and measured under the condition of the poor as the modeling of grey differential sequence, prediction error to the construction phase and correction of formwork elevation, finally Baita bridge successfully, smooth linear, indicate that the grey predictive control theory has strong adaptability and practicability. The stress monitoring was introduced and the working principle of the strain gauge, layout the stress measurement and monitoring method for monitoring network, stress monitoring results show that the measured stress and stress theory to maintain consistent regularity and the error is small, show that the parameter correction and error correction adaptive control theory, structure and construction of the actual state of state of similar degree is high.

【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.4

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