Optimal Design of Cable-Stayed Bridge Based on Construction Stage Analysis

The cable-stayed bridge is one of the most popular bridges types chosen by architects and structure engineers in modern bridge design because of its aesthetic appeal and economy. When designing cable-stayed bridge, lots of design variables such as cable force, pylon height, number of cables need to be decided. However, the design for these varibles usually focus on the completion stage of cable-stayed bridge but not construction stage, it might ignore the overvalue of stress ratio and joint displacements between the construction stage. In addition, as cable-stayed bridges are highly undetermined with severe nonlinearity, it might appear element damage and lack of constructability between construction stage easily. So it’s important to consider the design and analysis about the construction stage. The research start with structure optimization, algorithm and important variables of cable-stayed bridge. Then focus on the pros and cons between different construction methods, and introduce the types and installation method about the stay cables. After knowing the construction method and sequence, we can use SAP2000 to do the analysis about construction stage. The research divides the construction stage into two parts. One is new girder construction part, the other is cable stays installation part. The second part will use two different analysis method, Forward Analysis and Backward Analysis, to do the optimization of cable force. Moreover, we will put auxiliary stays about travelers and pylons into the construction stage analysis, and output the results and check with specifications. Finally, we finish the optimal design of cable-stayed bridge based on construction stage analysis. The research give an example of single pylon cable-stayed bridge in the last chapter. We use two construction analysis method, Forward Analysis and Backward Analysis, to do the optimization of cable force, and show the results of different methods in figures. We discuss the pros and cons about different methods and give some advises in design and construction of cable-stayed bridge. Design and construction of cable-stayed bridge is a tough task. The research is aimed at solving some specific problems of cable-stayed bridges and provide engineers some advises for cable-stayed bridge in design and construction.