Optimum design of steel box-concrete composite arch bridges based on improved genetic algorithms

In view of shortcomings such as premature convergence and oscillation in Simple Genetic Algorithms (SGA), the article adopts method of adaptive adjusting for the probabilities of crossover and mutation. So the Improved Genetic Algorithms (IGA) is formed by adding the transgenic operator to SGA. And the optimum design program of steel box-concrete composite arch bridges based on improved genetic algorithms is simultaneously developed. The structure optimum of steel box-concrete composite arch bridges is conducted by using IGA. The numerical experiment shows that the optimization result satisfies the structure design code, and the project cost is obviously reduced.