单索面钢桁梁独塔斜拉桥施工阶段动力参数分析

Analysis of Dynamic Parameters of Steel Truss Girder Cable-Stayed Bridge with Single Pylon and Single Cable Plane at Construction Stage

为研究单索面钢桁梁独塔斜拉桥结构参数对最大悬臂状态下桥梁动力特性的影响,以重庆某单索面公轨两用钢桁梁独塔斜拉桥为背景,运用有限元分析软件ANSYS建立全桥有限元模型,对其基本动力特性进行分析,并分析了主要构件刚度、斜拉索倾角及辅助墩位置变化对该桥动力特性的影响。结果表明:该桥主梁的竖向频率大于其横向频率,扭转刚度较小;主梁刚度的增加有助于提高结构的扭转刚度,增强结构的抗风稳定性,桥塔及斜拉索刚度的增加有助于提高结构的竖向弯曲刚度及侧弯扭耦合刚度;斜拉索倾角对结构的整体刚度影响较大,辅助墩的设置位置对大桥的抗风稳定性产生较大影响。

To study the influences of the structural parameters of the steel truss girder cablestayed bridge with a single pylon and single cable plane on the dynamic characteristics of the bridge in the state of the longest cantilever at the construction stage, a road-cum-light rail steel truss girder cable-stayed bridge with a single pylon and single cable plane in Chongqing was cited as an example, the software ANSYS was used to set up the finite element model for the whole bridge of the bridge and the basic dynamic characteristics of the bridge were analyzed. The stiffness of the principal components, the changing of the dip angles of the stay cables and the location of the auxiliary pier were also analyzed. The results of the analysis demonstrate that the vertical frequencies of the main girder of the bridge are greater than the transverse ones and the torsional stiffness is little. The increase of the stiffness of the main girder is helpful to the improvement of the torsional stiffness and wind stability of the structure. The increase of the stiffness of the pylon and stay cables is helpful to the improvement of the vertical bending stiffness and the coupling stiffness of the lateral bending and torsion. The dip angles of the stay cables have considerable influences on the global stiffness of the structure and the arrangement location of the auxiliary pier has consid-erable influences on the wind stability of the bridge.