摘要
采用振动法对杭埠河大桥平行钢绞线索进行了索力测试,分析了平行钢绞线索的离散性、垂度和区域性接触对索力测试的影响,采用逐步扩大法模拟平行钢绞线索的离散性。讨论了拉索自振频率的确定、面内面外振动的振动特性以及不同拾振器放置位置时的实测信号特征。基于有限元方法建立平行钢绞线索及钢绞线-HDPE套管接触耦合模型,进行了平行钢绞线索振动特性分析。结果表明:振动法可以用于平行钢绞线索索力测试,索力计算时应尽量采用低阶频率;钢绞线间的离散性和索力不均匀性对拉索振动影响较小,拉索面内振动受施工影响较大,钢绞线面外振动频谱特征更为明显,低阶振动分量较多且易识别,利用面外振动可以更好地确定拉索自振频率;考虑HDPE套管质量,修正拉索线密度可提高索力测量精度。
The cable tension of parallel strands in Hangbuhe Bridge is measured by vibration method, the impact of the discreteness, sag and regional contact of parallel strands on cable tension measurement is analyzed, and the discreteness of parallel strands is imitated by step by step enlargement method. Then, how to determine the natural frequency of cable, the vibration characteristics of in-plane vibration and out-of-plane vibration as well as the measured signal characteristics with different locations of sensor are discussed. The contact coupling model of parallel strands and strands-HDPE casing is established by finite element method, and the vibration characteristic of the parallel strands is analyzed. The result shows that （ 1 ） the vibration method can be adopted to measure the cable tension of parallel strands, low frequency should be used as far as possible to calculate the cable tension; （2） the discreteness and the non-uniform cable tension have less impact for cable vibration, in-plane vibration is greater affected by construction, the out-of-plane vibration of cable emerged the obvious vibration characteristics, more low-order vibration components are appeared and easily identified, the natural frequency of the cable can be better determined by out-of-plane vibration ; （3） the measuring accuracy of cable tension can be improved by modifying the line density of cable considering the mass of HDPE-casing.
出处
《公路交通科技》
CAS
CSCD
北大核心
2018年第2期55-61,共7页
Journal of Highway and Transportation Research and Development
关键词
桥梁工程
索力测试
振动法
平行钢绞线索
频率
bridge engineering
cable tension measurement
vibration method
parallel strand cable
frequency
