基于磁弹法的连续刚构桥预应力无损检测技术研究

发布时间：2018-02-02 10:44

本文关键词： 磁弹法连续刚构桥有效预应力摩阻系数无损检测　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着桥梁建设的迅速发展,在役或在建的大跨度预应力混凝土连续刚构桥日趋增多。但在役的连续刚构桥普遍存在主跨跨中下挠的问题,直接影响行车的安全性和舒适性,目前达成的一致共识是,此病害的主要原因是纵向预应力损失过大导致的。然而,引起预应力损失的因素很多且各因素间相互影响,致使精确计算预应力总损失变得非常复杂且难度大,通过有效检测手段检测预应力损失的研究方兴未艾。现在也有一些有效预应力检测方法的研究成果,但可用于实际工程且检测精度高、抗干扰能力强、稳定性好的无损检测方法极少。因此,本文重点针对基于磁弹法的连续刚构桥预应力无损检测技术进行研究,旨在通过研究,提出检测应用技术,验证磁弹法检测连续刚构桥有效预应力的可靠性及适用性,为今后同类桥梁预应力检测方法的进一步研究及实桥应用提供一定的依据。本论文研究的主要内容包括:①在介绍磁弹法检测原理的基础上,研究磁弹传感器应用于连续刚构桥检测的设计方法、准则、温度影响机理及温度修正方法;②分析研究磁弹法检测连续刚构桥有效预应力现场应用技术,包括磁弹传感器布置技术、安装工艺、磁弹传感系统现场检测技术以及检测精度影响因素和解决方法;③结合依托工程,利用磁弹传感器针对云南省昭通市新建牛栏江特大桥进行现场预应力张拉阶段试验钢束有效预应力测试。同时选取顶板束和腹板束进行管道摩阻试验,分析张拉阶段顶板束和腹板束管道摩阻系数的变化规律,提出?、k的合理取值范围,并给出预应力摩擦损失建议修正公式;④根据04规范计算施工期间试验钢束的理论预应力损失值,建立Midas Civil有限元模型,分别将管道摩阻系数04规范规定值及现场测试值赋予有限元模型,比较分析现场实测值、理论计算值以及模型值,得到预应力损失的基本规律,分析误差原因,得出相关结论。同时以此验证和研究磁弹法检测连续刚构桥有效预应力的可靠性及适用性。
[Abstract]:With the rapid development of bridge construction, there are more and more long-span prestressed concrete continuous rigid frame bridges in service or under construction. It directly affects the safety and comfort of driving. The consensus is that the main cause of this disease is the loss of longitudinal prestressing force. There are many factors that cause the loss of prestress, and each factor affects each other, so it is very complicated and difficult to calculate the total loss of prestressing force accurately. The research of detecting the loss of prestressing force by effective detection method is in the ascendant. There are also some research achievements of effective prestress detection method, but it can be used in practical engineering and has high detection precision and strong anti-interference ability. There are few non-destructive testing methods with good stability. Therefore, this paper focuses on the research of the non-destructive testing technology of prestressed continuous rigid frame bridge based on magnetoelastic method, aiming to put forward the testing application technology through the research. Verify the reliability and applicability of magnetoelastic method to detect effective prestress of continuous rigid frame bridge. The main contents of this paper include the introduction of the Magnetoelastic testing principle in this paper, which is based on the introduction of the principle of Magnetoelastic testing. The design method, criterion, temperature influence mechanism and temperature correction method of magnetoelastic sensor applied to continuous rigid frame bridge detection are studied. (2) the field application technology of magnetoelastic method to detect the effective prestress of continuous rigid frame bridge, including magnetoelastic sensor arrangement technology and installation technology, is analyzed and studied. The field detection technology of magnetoelastic sensing system and the influencing factors and solving methods of testing precision; (3) combining support engineering. The magnetoelastic sensor is used to test the effective prestress of the steel bundle in the field of the new Niulanjiang Bridge in Zhaotong, Yunnan Province. At the same time, the friction test of the pipe is carried out by selecting the roof bundle and the web bundle. This paper analyzes the variation law of friction coefficient of roof bundle and web bundle pipeline in tension stage, and puts forward? The reasonable value range of k is given, and the modified formula of prestress friction loss is given. (4) according to the 04 code, the theoretical prestressing loss value of the test steel bundle is calculated, and the Midas Civil finite element model is established. The finite element model is assigned to the specified value of the friction coefficient 04 and the field test value respectively. The field measured value, the theoretical calculation value and the model value are compared and analyzed, and the basic law of the prestress loss is obtained. Based on the analysis of the error reasons and the relevant conclusions, the reliability and applicability of the magnetoelastic method for detecting the effective prestress of continuous rigid frame bridges are verified and studied.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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