Comprehensive Method Of Determining Reasonable Cable Forces Of Completion State Of Bridge Of The Cable-Stayed Bridges

Cable-stayed bridge is highly redundant complex structure and its cable forces have influence on the distribution of internal force of the whole structure system and they have become the key to control the forces of the whole bridge. So, how to reasonably determine cable forces to make the suffered force state of the cable-stayed bridge rational has become the key point in the design of the cable-stayed bridges. Now many scholars at home and abroad have brought forward a lot of methods to determine reasonable cable forces of the cable-stayed bridge and each method has its character and condition. Several methods of determining reasonable cable force of cable-stayed bridges have been primarily analyzed and studied in this paper, a comprehensive method that takes Rigidity Supporting Continuous Beam method together with Minimum Bending Energy method is proposed on the based of this.Through analysis in theory and calculation on real cable-stayed bridges, following conclusions have been reached: 1) Methods of modeling cable-stayed bridges for nonlinear finite element analysis are reasonable and effective and truss and beam element has enough accuracy. 2) Calculation essence of reasonable cable force is equivalent to optimization calculation on force status of cable-stayed bridges under dead weight. Getting reasonable results are depended on not only calculation method and process but also structure design parameters that are structure dimension and form and material characters and so on and they should meet with a certain condition. 3) Different expectant targets determine different methods of determining reasonable cable force. Only making using of a certain method inevitably has disadvantage and shortcoming. Reasonable results can be attained through some methods because controlling conditions are not adopted reasonably. Adopted comprehensive method in this paper is compact and effective. 4) Because completed status of the bridge of the cable-stayed bridges is relative, minimum Bending strain Energy of main beam and tower is considered as optimum object and reasonably suffered force of main beam and tower and uniform cable forces also have been considered at the same time in this method.5) The comprehensive method can avoid the limitation of only using a I certain method.