何旭辉, 汪震, 刘路路, 等. 牛角岩平拉索桥风致振动现场调研与分析[J]. 空气动力学学报, 2023, 41(2): 83−89. doi: 10.7638/kqdlxxb-2022.0044
引用本文: 何旭辉, 汪震, 刘路路, 等. 牛角岩平拉索桥风致振动现场调研与分析[J]. 空气动力学学报, 2023, 41(2): 83−89. doi: 10.7638/kqdlxxb-2022.0044
HE X H, WANG Z, LIU L L, et al. Field investigation and analysis of wind-induced vibration of Niujiaoyan cable-suspended bridge[J]. Acta Aerodynamica Sinica, 2023, 41(2): 83−89. doi: 10.7638/kqdlxxb-2022.0044
Citation: HE X H, WANG Z, LIU L L, et al. Field investigation and analysis of wind-induced vibration of Niujiaoyan cable-suspended bridge[J]. Acta Aerodynamica Sinica, 2023, 41(2): 83−89. doi: 10.7638/kqdlxxb-2022.0044

牛角岩平拉索桥风致振动现场调研与分析

Field investigation and analysis of wind-induced vibration of Niujiaoyan cable-suspended bridge

  • 摘要: 颤振是大跨度桥梁结构设计的控制性因素之一,一直备受关注;而实桥发生颤振的记载十分稀少,现场音视频记录和振后调研资料十分珍贵。2021年5月1日下午2时许,贵州省思南县香坝镇牛角岩地区两座平拉索桥发生剧烈颤振。本文通过振后桥梁状况的现场调研,发现大幅的弯扭耦合颤振使得桥梁各个构件受损严重,其中1#桥背风侧承重索和稳定索明显伸长,2#桥承重索与稳定索发生断裂;1#桥背风侧主梁低于迎风侧,主梁产生相对高差并发生倾斜,相对高差与扭转角由两岸向跨中不断增加,跨中最大值分别为0.480 m和4.58°。通过对比现场测量与有限元模型分析发现:竖弯与扭转频率在颤振发生前后变化较小,而横摆频率显著减小。现场视频记录分析表明,桥梁发生典型的弯扭耦合颤振,竖向振幅约为5.2 m,扭转振幅约为52°,竖向与扭转振动相位差约为90°;颤振发生时,主梁竖向振动的动能、扭转振动的角动能与势能不断转换,当动能最大时,角动能与势能最小。

     

    Abstract: Flutter has been of great interest as one of the control factors in the design of long-span bridges. There are very few flutter recordings of real bridges, hence the audio and video recorded on site and post-vibration studies about flutter are invaluable. At around 2 pm on May 1st, 2021, two cable-suspended bridges in the Niujiaoyan area of Xiangba Town, Sinan County, Guizhou Province, were subjected to violent flutters. This study analyzes the response characteristics of these flutters and summarizes the field investigation of the bridge condition after the flutter. It is found that the large bending-torsional coupled flutter causes severe damage to the bridge elements, including the significant elongation of the bearing and stable cables on the leeward side of bridge 1#, and the fracture of the bearing and stable cables on bridge 2#. The relative height difference and the torsion angle increase continuously from the two sides to the mid-span, reaching the maximum values of 0.480 m and 4.58°, respectively, at the mid-span. By comparing the dynamic characteristics of the bridge under the field measurement and the finite element modelling, it is found that the bending and torsion frequencies change little after the flutter, while the transverse frequency decreases significantly. Analyses of the flutter videos recorded in the field show that the flutter is a classic bending-torsion coupled flutter with a vertical amplitude of about 5.2 m and a torsional amplitude of about 52°, and the phase difference between the vertical and torsional vibrations is about 90°. When the flutter occurs, there is a constant conversion among the kinetic energy of the vertical vibration, the angular kinetic energy of the torsional vibration and the potential energy; when the kinetic energy is at its maximum, the angular kinetic energy and potential energy are at the minimum.

     

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