Analysis On Reasonable Bridge Condition And Structure System Of Cable-stayed Bridge

As a kind of indeterminate flexible structure, we can adjust internal force and deformation by adjusting the tension of cable which are caused by the cable-stayed bridges weight. So, deformation state and dead load internal force which can meet requirement of design should be set by structural analysis and cable forces adjusting in completed bridge phase which is the so-called reasonable finished dead state,after structure size and discharge is determined in the design process of cable-stayed bridge; then the reasonable finished dead state would be regarded as target state to search rational construction state and determine the reasonable construction process. A set of cable force would be found which could make the bridge in the reasonable finished state through the optimization design of cable-stayed bridge. So, the main work of reasonable bridge state determineation is to determine a set of cable force by optimization design. Meanwhile, the selection of structure systems not only needs to meet the requirements of the stress, but also need to match landform, span, economic condition and so on.The development history and tendency of cable-stayed bridge have been summarized, and the author also described the structure characteristic and structural system category of cable-stayed bridge. Some common determination methods of rational cable force were summarized whose advantages and disadvantages of analysis were compared, consulting evaluation index of reasonable finished dead state in the Guidelines for Design of Highway Cable-stayed Bridge(JTG D65-01-2007). In this paper, determination method of rational cable force based on the combination of main girder force balance method of cable force influence matrix and rigid supported continuous beam method was elaborated whose advantages and implementation process were also introduced.Geometric nonlinear issues and finite element analysis theory of Cable-stayed bridge have been summed, The finite element solution principle of geometric nonlinear problem for cable-stayed bridge structure has been employed to summarized whose implementation was also declared.Based on the actual project,rational cable force determination method which is based on the cable force influence matrix was used in the design process of long-span prestressed concrete cable-stayed bridge, feasibility of this method has been proved by the comparison between calculated cable force and designed cable force. Calculation analysises of finished bridge and operation stages for this project, including statical analysis, dynamic analysis, stability calculation and cable tower and substructure analysis have been carrird on from the perspective of cable-stayed bridge design,which have certifyed that Cable-stayed bridge could meet the design and specifications requirements in the action of the calculated final hanger force.The classification and design principles of cable-stayed bridge structure system have been concluded.Double pylon cable stayed bridge structure system is analyzed combining the design process of selected project. The cable bridge phase static analysis comparison results of the side span auxiliary pier Settings and decorate a form has been respectively analyzed.Through the results of structural system change on the analysis, the influence of force characteristics of cable-stayed bridge has been summarized.It provides design reference for the selection of future cable-stayed bridge structure system.