Stability Analysis Of Large Span Cable-stayed Bridge

With the increase of the span of cable-stayed bridges, their towers become more taller and their girders stiffened tend to be more thiner. As a result the axial pressure of the towers and girders increases sharply . Furthermore, the effects of sag and the geometric nonlinearity and the material nonlinearity increase in apparently. These disadvantageous factors decrease the safety coeffient of cable-stayed bridges, which makes the stability of cable-stayed bridges very important. The paper has applied finite element method to analyze the first kind of stability and the second of kind stability of cable-stayed bridges. On the base of it, the long-span prestressed concrete cable-stayed bridge (Dafosi River Bridge of ChongQing) has been taken as an example to research and compare the two kinds of stability during the cantilever construction and in use. Furthermore, this paper has presented a model experiment research on the stability of the bidge during the largest cantilever construction. By analyzing and comparing the coincidence between the theoretical calculations and the results of the model experiment, whether the calculating method and design theory are right or not has been confirmed. Thereby, this provides practical reference for design, construction and scientific research of long-span cable-stayed bridges.