Study On Reasonable Cable Forces Under Dead Load For Special-Shaped Steel Cable-stayed Bridges

It is a key problem to determine the reasonable cable forces in designing cable-stayed bridges, which has been one of the hot subjects to researchers all around the world for many years. New ideas, solutions and theories have come out every now and then; furthermore, all these are put into practice, tested and modified. At the very beginning, this thesis looks back the development of the cable-stayed bridges, introduces the analysis theory, brings in the conception of cable forces optimization, and lists the present methods of determining reasonable cable forces under dead load.Next, discusses the various classified methods, analyzes these ways'appropriate conditions, concludes their advantages and disadvantages by comparison, and indicates the problems in applying these normal approaches to special-shaped steel cable-stayed bridges and reaches a conclusion.Then, the author creates the model with the FEM, and according to the cable forces optimization theory, which determines the cable forces in the complete state on the basis of the construction supervision on a certain bridge.Furthermore, the author analyzes and discusses the shortcoming of each reasonable cable forces thesis in special-shaped steel cable-stayed bridges. Meanwhile, aiming at special-shaped steel cable-stayed bridges design and analysis, the author issues a clearer, more accurate two-level cable forces optimization method by the least bending energy and stress balance method within a certain range of stress and line shape, embed plane shell element in finite element model, and points out the necessary technique and difficult points.In the end, calculation and discussion are concluded and further research is issued.