The Whole Stability Analysis Of The Single Tower Composite Beam Cable-stayed Bridge

The cable-stayed bridges, a kind of determinate flexible structure with many redundant degrees, consists of three basic members:towers, cables and girders. Towers and girders are the structures which endure compressed and bended force when the cables undergo force, so the stability of the bridge should be considered. Because of its variant inner force under dead-load, nonlinear behavior and the correlation between construction method and completed structure, the construction stability analysis and nonlinear analysis that consider those factors become very important in the design of cable-stayed bridge.In this paper, it take the SongPu Bridge as background to analyze the stability of composite beam cable-stayed bridge with single tower and double cable planes by the general finite element software. The main work has been completed as followings:1. The stability theory of cable-stayed bridge are described in this paper. The evaluating index, unstable criteria are also studied. The paper has discussed the solution for the various nonlinear on the cable-stayed stability and introduced the way to analyze elastic and nonlinear stability of cable-stayed bridge by ABAQUS.2. The paper adopts the general finite element software ABAQUS to establish the space model of the Songpu bridge, then to analyze the linear and geometrical nonlinear whole stabilities under construction. The nonlinear analysis considers only geometric nonlinearity and geometric and material nonlinearities.3. Evaluated the overall stability of the Songpu bridge according to solution of the linear elastic stability and nonlinear stability of longest double cantilever, single cantilever and the dead load states, considering all kinds of nonlinear factors, the buckling types and the most possible destroyed forms of the representative phases are also pointed.4. The structural parameters, construction factors, the number and the location of auxiliary piers which affect the cable-stayed bridge's whole stability are analyzed and can be used as the reference of design and construction.