Optimal design of semi-fan cable-stayed bridges

The design of cable-stayed bridges is generally controlled by a large number of design variables and constraints, making the traditional design methods sophisticated, expensive, and time consuming. Moreover, the conventional design methods could not guarantee the cost optimality of the final solution. In this study, a numerical design tool that integrates a finite element model, genetic algorithm, simple polynomial functions for evaluating post-tensioning cable forces, and design methodologies is developed specially to optimize the design of cable-stayed bridges. The loads, design, and constraints used in the numerical model are developed based on the Canadian Highway Bridge Design Code CAN/CSA-S6-06. The efficiency and practicality of the proposed numerical design tool have been demonstrated by optimizing a practical sized cable-stayed bridge.