大跨度预应力混凝土连续梁桥预应力损失及敏感性分析

发布时间：2018-01-16 17:27

本文关键词：大跨度预应力混凝土连续梁桥预应力损失及敏感性分析　出处：《石家庄铁道大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着悬臂施工方法在连续梁桥施工中地应用,预应力混凝土连续梁桥在全国范围内得到普及。悬臂施工过程比较复杂,在施工过程中主梁线形必然会发生变化,给施工监控工作增添难度。施工监控主要内容是对施工过程中的各参数进行监测和处理。为提升施工监控精度,论文以广东省佛山市华阳特大桥为工程背景,对悬浇施工阶段影响线形的参数进行敏感性分析,主要的研究内容如下:(1)基于华阳特大桥的施工步骤和有限元基本原理,利用有限元仿真软件Midas/Civil建立仿真模型,对该桥的施工阶段进行仿真分析,获得主梁在各个施工阶段的理论标高值和预应力损失值;(2)利用仿真模型,对悬臂浇筑施工阶段影响主梁线形的参数:混凝土容重、混凝土弹性模量、张拉控制应力、管道摩阻系数、施工荷载、混凝土收缩徐变,进行敏感性分析,找出悬浇施工阶段影响主梁线形的主要参数以及各参数对线形的影响程度;(3)根据施工工况设计主梁标高监测方案,测得各个工况下主梁标高值并与模型计算值进行比较,验证仿真模型的合理性;利用磁通量传感器对部分预应力钢束进行监测,获得各个施工阶段钢束的有效应力值与模型计算值进行比较分析;(4)结合工程实际施工情况,分析在施工过程中出现某梁段混凝土容重发生变化,某钢束预应力损失值增加,管道摩阻参数发生变化的情况对后续施工阶段的影响。给予施工单位合理的解决方案,指导后续施工阶段施工,为施工监控工作提供参考数据;(5)将分析得出的实测预应力损失规律推广至未监测预应力钢束,并将得到的钢束有效应力值带入模型中,求出实测有效应力值所引起的标高差值占桥面实测标高差值的比例。
[Abstract]:With the application of cantilever construction method in the construction of continuous beam bridge, prestressed concrete continuous beam bridge is popularized throughout the country. The cantilever construction process is more complex, and the main beam alignment will inevitably change during the construction process. The main content of construction monitoring is to monitor and deal with the parameters in the construction process. In order to improve the construction monitoring accuracy, the paper takes Huayang Bridge in Foshan City, Guangdong Province as the engineering background. The sensitivity analysis of the parameters affecting the line shape in the construction stage of suspended casting is carried out. The main research contents are as follows: 1) based on the construction steps of Huayang Bridge and the basic principle of finite element. The finite element simulation software Midas/Civil is used to establish the simulation model, and the theoretical elevation value and the prestress loss value of the main beam in each construction stage are obtained by the simulation analysis of the bridge construction stage. 2) using the simulation model, the parameters that affect the alignment of the main beam in the construction stage of cantilever pouring are as follows: bulk density of concrete, elastic modulus of concrete, tension-controlled stress, friction coefficient of pipeline, construction load, shrinkage and creep of concrete. The sensitivity analysis is carried out to find out the main parameters which affect the alignment of the main beam in the construction stage of suspended casting and the influence degree of each parameter on the alignment. (3) according to the construction conditions, the main beam elevation monitoring scheme is designed, the main beam elevation values under each working condition are measured and compared with the calculated values of the model, and the rationality of the simulation model is verified. The magnetic flux sensor is used to monitor the prestressing steel strands, and the effective stress values of the steel strands in each construction stage are compared and analyzed with the calculated values of the model. 4) combined with the actual construction situation of the project, it is analyzed that the concrete bulk density of a beam section changes during the construction process, and the prestressing loss value of a certain steel beam is increased. The influence of the change of pipeline friction parameters on the subsequent construction stage. Give the reasonable solution to the construction unit, guide the construction in the subsequent construction phase, and provide reference data for the construction monitoring work; Finally, the law of the measured prestress loss is extended to the unmonitored prestressed steel bundle, and the effective stress value of the steel beam is brought into the model. The proportion of the elevation difference caused by the measured effective stress value to the measured elevation difference value of the bridge deck is obtained.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.57

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