Structural Optimization of a Steel Arch Bridge with Genetic Algorithm

Structural optimization has become an important tool for structural designers. It helps the designers to find optimal design solutions with better exploitation of materials subject to various constraints. In this article, to face the critical issue of huge horizontal thrust occurred in the Calatrava bridge over the Grand Canal of Venice, single-objective and multi-objective genetic algorithm (GA) based optimization procedures are set up, and the thickness optimization of the bridge is carried out separately with the proposed design procedures and the optimization module implemented in ANSYS. The results are compared in terms of steel volume and horizontal thrust level. It shows that the GA-based design procedures are effective tools to achieve optimal design due to the global search ability of GA. Further, with these powerful tools, more reasonable thickness distributions of steel plates and tubes of the Calatrava bridge can be obtained, meanwhile, the horizontal thrust can be reduced remarkably, and hence the high cost due to the large horizontal thrust of original design could be reduced.