大跨度连续梁桥施工控制及基于响应面法的参数敏感性分析

发布时间：2018-03-06 12:46

本文选题：连续梁桥　切入点：施工控制　出处：《北京交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：为保证连续梁桥的成桥线形、应力状态与理想状态很好的吻合,以及结构在悬臂施工过程中的安全与稳定,桥梁施工控制受到了越来越多的重视。本文以陇海路主线南幅桥为工程背景,对大跨径预应力混凝土连续梁桥施工控制进行研究,主要研究内容及结论如下： 1、基于有限元原理及陇海路主线南幅桥施工特点,利用Midas软件建立有限元模型,对该桥进行施工过程模拟分析,得出桥梁变形及控制截面的应力状态； 2、结合本工程受力特征及施工进度,编制施工监控方案,对大桥的施工全程进行监控。其监控项目主要包括应力、线形、温度及临时支墩稳定性监控。通过有效的施工控制,各应力监测断面实际应力状态随施工进程发展状况符合预期设计目标、线形符合设计要求、温度变化对梁体扭转变形较小、T构两侧临时支墩变形基本一致且稳定性较好； 3、在应力监控中,对实测应力计算方法进行了研究。本文实测应力计算考虑阶段施工中收缩、徐变的影响,并用Matlab进行编程计算。通过比较分析,考虑混凝土收缩、徐变所得的实测应力与计算值差别较小,按此方法由实测应变得到桥梁的真实应力状态是可行的； 4、线形控制的主要工作之一就是提供立模标高。为提高立模标高管理工作效率,确保数据信息的准确性与安全性,本文基于Access建立立模标高管理系统； 5、本文提出了基于响应面法的参数敏感性分析方法,简化了参数敏感性分析过程。通过对陇海路主线南幅桥的参数敏感性分析可知,所选影响参数对结构状态的影响基本呈线性关系,且在不同施工阶段影响程度不同。总体来说,对挠度的敏感性而言,混凝土弹性模量和截面抗弯惯性矩为主要影响参数,混凝土容重和预应力为次要影响参数；对截面应力的敏感性而言,混凝土容重和预应力为主要影响参数,抗弯惯性矩和混凝土弹性模量为次要影响参数。
[Abstract]:In order to ensure the bridge shape of continuous beam bridge, the stress state is in good agreement with the ideal state, and the structure is safe and stable in the process of cantilever construction. More and more attention has been paid to bridge construction control. In this paper, the construction control of long-span prestressed concrete continuous beam bridge is studied with the main line of Longhai Road as the engineering background. The main research contents and conclusions are as follows:. 1. Based on the finite element principle and the construction characteristics of the main line of Longhai Road, the finite element model is established by using Midas software, and the bridge deformation and the stress state of the control section are obtained by simulating and analyzing the construction process of the bridge. 2. According to the stress characteristics and construction schedule of the project, the construction monitoring scheme is worked out to monitor the whole construction of the bridge. The monitoring items mainly include stress, line shape, temperature and the stability of temporary piers. The actual stress state of each stress monitoring section accords with the expected design objective with the development of the construction process, the linear shape accords with the design requirements, and the temperature change is basically consistent and stable to the deformation of the temporary pier on both sides of the beam with small torsional deformation. 3, in the stress monitoring, the calculation method of the measured stress is studied. In this paper, the effect of shrinkage and creep in the construction stage is considered in the calculation of the measured stress, and the program calculation is carried out with Matlab. Through comparison and analysis, the shrinkage of concrete is considered. The difference between the measured stress and the calculated value is small, so it is feasible to get the true stress state of the bridge from the measured strain by this method. 4. One of the main tasks of linear control is to provide vertical die elevation. In order to improve the efficiency of vertical die elevation management and ensure the accuracy and security of data information, this paper establishes a vertical die elevation management system based on Access. 5. In this paper, a parameter sensitivity analysis method based on response surface method is proposed, which simplifies the process of parameter sensitivity analysis. The influence of the selected parameters on the structural state is linear, and the influence degree is different in different construction stages. In general, the elastic modulus of concrete and the bending moment of inertia of the section are the main influencing parameters for the sensitivity of deflection. The concrete bulk density and prestress are the secondary influencing parameters, the concrete bulk density and prestress are the main influencing parameters, and the moment of inertia and the elastic modulus of concrete are the secondary influence parameters.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.215;U445

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