某大跨径斜拉桥自振特性研究

Analysis of Self-vibration characteristics of long-span cable-stayed Bridges

以某双塔组合梁斜拉桥为工程背景,利用桥梁结构分析专用软件Midas/Civil建立全桥三维有限元模型,对大桥各阶振型与自振频率进行分析研究,与实际测试分析的频率及振型进行对比。结果表明:桥梁实际振动形式较为复杂,实测频率较低,桥梁总体刚度较小,但桥梁实测振型与理论计算振型基本相符,实际测试频率大于理论计算值,说明结构刚度整体较大,满足设计要求。

Based on the engineering background of a twin-tower composite beam cable-stayed bridge,The natural vibration characteristics of the bridge are calculated,analyzed and studied.The three-dimensional model of the bridge is established by using the special program Midas/Civil for bridge structural analysis.The natural vibration frequency and mode of the bridge are calculated,and co MPared with the measured frequency and mode.The results show that the measured values of the modal parameters of the bridge are basically consistent with the theoretical design values,and the measured frequencies are slightly higher than the calculated values,indicating that the overall structural stiffness is large and meets the design requirements.