两种特殊构造斜拉索的索力测试方法研究

发布时间：2018-01-09 19:06

本文关键词：两种特殊构造斜拉索的索力测试方法研究　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：基于弦理论的振动频率法是目前工程中应用最为广泛的索力测试方法。在常规的斜拉索索力测试中，振动频率法的精度基本能够满足要求。但对于安装有外置阻尼器的斜拉索，以及带有HDPE外壳的钢绞线斜拉索，常规的索力测试方法是否还适用，目前这方面的研究较少。针对这两种特殊构造斜拉索的索力测试方法，本文依托两座特大跨径斜拉桥开展研究，，取得了以下主要成果： ①基于厦漳跨海大桥斜拉索的测试数据和理论计算，对斜拉索的弯曲刚度、垂度参数识别进行了讨论，并就其对索力测试的影响进行了分析。分析结果表明，实桥的平行钢丝斜拉索的弯曲刚度值取值在0.33EImax~0.54EImax之间。弯曲刚度对长索的索力测试影响较小。垂度对长索的对面外频率没有影响，对面内基频影响较大。 ②以厦漳跨海大桥10根厦漳跨海大桥斜拉索为例，运用基于复特征值的有限元法，主要考虑外置阻尼器的阻尼系数对拉索面内振动频率的影响，绘制了拉索阻尼器—频率影响曲线，该影响曲线具有明显的上升段、平稳段、微下降段的三段性特征。分析结果表明，在阻尼系数对拉索面外振动频率没有影响，对面内振动基频的影响很小，高阶频率影响较大。 ③通过实测数据的频谱分析表明，安装外置阻尼器的斜拉索索力测试时，拾振器的合理安装位置为，阻尼器以上且与阻尼器的距离大于阻尼器与桥面的距离的拉索上。实桥索力测试，可以通过频率反算修正系数考虑主梁-拉索-阻尼器耦合振动，来提高索力测试精度。 ④针对带HDPE外壳的钢绞线斜拉索的索力测试问题。计算结果表明，钢绞线约束圈具有良好的传递振动信号的能力，将拾振器安装在钢绞线拉索约束圈对应位置的HDPE外壳上，可以有效识别钢绞线斜拉索的振动信号。经东水门长江大桥的钢绞线斜拉索索力测试的现场验证，该方法效果良好。
[Abstract]:Vibration frequency method based on string theory is the most widely used method in engineering at present. The accuracy of the vibration frequency method can meet the requirements basically, but for the cable with external damper and the cable with HDPE shell, the conventional cable force test method is also applicable. At present, there is little research on this aspect. In view of the cable force test methods of these two special structural cable-stayed cables, this paper carries out the research based on two extraordinarily large span cable-stayed bridges, and obtains the following main results: 1 based on the test data and theoretical calculation of stayed cables of Xiazhang cross-sea bridge, the identification of bending stiffness and sag parameters of stayed cables is discussed, and the influence of them on cable force test is analyzed. The bending stiffness of parallel steel wire stay cables of real bridge is between 0.33 EImax0. 54 EImax. The flexural stiffness has little effect on the cable force test of long cables. It has an impact. The influence of internal fundamental frequency on the surface is great. 2 taking 10 cables of Xiazhang cross-sea bridge as an example, the finite element method based on complex eigenvalue is used to consider the influence of damping coefficient of external dampers on the vibration frequency of cable plane. Draw the cable damper-frequency influence curve, this influence curve has the obvious rise section, the stationary section, the microdescent section three stage characteristic. The analysis result shows. The damping coefficient has no effect on the vibration frequency outside the cable plane, but has little effect on the fundamental frequency of the vibration in the opposite direction, but the higher order frequency has a great influence on the vibration frequency. (3) the spectrum analysis of the measured data shows that the reasonable installation position of the vibration pick-up is when the cable force of the cable is tested by installing the external damper. Above the damper and the distance from the damper is larger than the distance between the damper and the bridge deck. The cable force measurement of the real bridge can consider the coupling vibration between the main girder and the cable damper through the frequency inverse correction coefficient. To improve the precision of cable force testing. 4 for the cable force test problem of the steel strand cable with HDPE shell, the calculation results show that the strand restraint ring has a good ability of transmitting vibration signal. Install the vibration pick-up on the HDPE housing in the corresponding position of the cable restraint ring of the steel strand. The vibration signal of the cable can be recognized effectively. The method is proved to be effective by the field test of the cable force of the steel strand of Dongshuimen Yangtze River Bridge.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27;U441

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