Database for the optimum design of semi-fan composite cable-stayed bridges based on genetic algorithms

The optimum design solution of cable-stayed bridges is a complicated task. The large number of design parameters, strict design constraints imposed by design codes, highly geometrically nonlinear behaviour and robust effect of post-tensioning cable forces make traditional design methods not capable of achieving this task. In this study, an optimisation technique that integrates a finite element model, a genetic algorithm and polynomial functions for evaluating post-tensioning cable forces is adopted to develop a database for the optimum design of cable-stayed bridges. The database describes the variations of the optimum design parameters, including the main span length, height of the pylon, number of stay cables and cross-sectional dimensions of all elements with the total length of the bridge. The study concerns the optimisation of three-span composite cable-stayed bridges with semi-fan cable arrangements. The study covers bridge lengths ranging from 250 to 700 m. The database is presented in the form of simple design charts and tables. Such database is useful in the preliminary design and cost estimation for this type of bridges.