Arch Axis Optimum Design of Steel Box-Concrete Composite Arch Bridge Based on Improved Genetic Algorithms

In view of shortcomings such as premature convergence and oscillation in Simple Genetic Algorithms (SGA), the article adopts the 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 bridge based on improved genetic algorithms is simultaneously developed. The arch section optimum of steel box-concrete composite arch bridge is firstly conducted by using the program. Then the arch axis optimum is conducted by using the optimized arch section parameters. Recomputation of the optimized steel box-concrete composite arch bridge is conducted by using the fem program in the end. The numerical experiment shows that the optimization result meets the demands, the mechanical behavior of arch rib is improved and the project cost is obviously reduced.