PC斜拉式桁架梁桥动力特性

Dynamic characteristics of PC cable stayed truss bridge

基于有限元理论,以某PC斜拉式桁架梁桥为工程实例,采用等效有限元法,建立三维有限元模型,对该结构进行动力计算分析。研究了桥墩刚度、横系梁刚度、桁架片刚度、桥墩高度、桥面宽度等参数对结构动力特性的影响,通过对结构的自振振型及频率进行相应分析,得出结构参数变化对结构的横向刚度、竖向刚度、纵向刚度和扭转刚度及其他动力特性的影响程度及规律。结果表明:桥墩的高度及刚度很大程度上决定了结构的纵向刚度,而横系梁的刚度是影响结构的横向刚度及抗扭刚度的主要因素。

Based on the theory of finite-element, a PC cable stayed truss bridge was taken as the studying case,a 3D finite-element model was built by the equivalent finite-element method. After studying the curve of the vibration frequencies, which are varying with the changing of the structural parameters such as the rigidity of pier, the rigidity of straining beam, the rigidity of truss, the high of pier, the width of deck, and so on, some rules about the changing of vibration frequencies and the influencing of the structure that vary with the parameters were achieved. The results indicate that the high and the rigidity of pier greatly affect the structure＇s longitudinal rigidity, and the rigidity of straining beam decide the structure＇s transverse rigidity and torsion rigidity. 2 tabs, 11 figs, 6 refs.