三塔混凝土主梁单索面斜拉桥动力特性分析

Analysis on Dynamic Properties of Three-tower Concrete Girder Cable-stayed Bridge with Single Cable Plane

以一座主跨跨径为300 m的三塔混凝土主梁单索面斜拉桥为工程背景,利用有限元程序建立该桥的空间梁单元模型,采用子空间迭代法进行了动力特性分析。分析结果表明,三塔混凝土主梁单索面斜拉桥的桥塔和主梁的振动存在明显的耦合特点;在桥梁边跨主梁下方设置辅助墩会提高桥梁的竖向刚度,影响三塔斜拉桥主梁的竖向振动;中塔处的塔梁固结约束对主梁的纵飘振动影响明显;主梁刚度对桥梁振型的影响不大,但会改变桥梁的自振频率。

Taking a three-tower concrete girder single cable plane cable-stayed bridge with the main span of 300 m as the engineering background, the space beam element model of the bridge was established by using the finite element program, and the dynamic properties was analyzed by spatial iteration method. The results showed that the vibration of the bridge tower and the girder had obvious coupling characteristics. Setting auxiliary piers under the girder of the side bridge span could improve the vertical rigidity and affect the vertical vibration of the main girder. The consolidation constraint of tower girder at middle tower had obvious effect on the longitudinal vibration of the main girder. The rigidity of main girder had little effect on the vibration mode of the bridge, but it would change the natural vibration frequency of the bridge.