大跨悬索桥施工过程颤振稳定分析

随着悬索桥跨径的不断增大，抗风稳定性成为控制桥梁设计与施工的最主要因素。尤其是在施工初期，结构的刚度比成桥要低得多，使得颤振临界风速最低，更容易发散。通过对主梁非对称拼装顺序以及采用临时的水平交叉加劲措施等方法的研究，讨论如何提高桥梁施工过程的颤振临界风速。分析结果表明，当主梁采用非对称施工时，会有效提高结构的等效质量，从而提高临界风速。当采用水平交叉索时，结构的抗扭刚度显著增加，同样增强了桥梁施工过程中的抗风稳定性。

Flutter Stability Analysis of Long-span Suspension Bridges during Erection

With the increase of span,aerodynamic stability becomes the most important factor in designing and constructing suspension bridges.Especially,during the construction period,the stiffness of structure is often less than that of the final state.Thus the flutter critical wind speeds are much lower and the bridge is more unstable during this period.The solutions to improve the critical wind speed are introduced by analysing the effect of non-symmetric erecting deck sequence and the method of temporary horizontal cross-cables.According to the analysis,the equivalent mass is increased by choosing the asymmetric erecting sequence,and the torsion stiffness is increased by using the temporary horizontal cross cables,both of them can improve the flutter critical wind speeds.