Optimal design of steel¿concrete composite bridge based on a transfer function discrete swarm intelligence algorithm

Abstract

[EN] Bridge optimization can be complex because of the large number of variables involved in the problem. In this paper, two box-girder steel¿concrete composite bridge single objective optimizations have been carried out considering cost and CO¿ emissions as objective functions. Taking CO¿ emissions as an objective function allows adding sustainable criteria to compare the results with cost. SAMO2, SCA, and Jaya metaheuristics have been applied to reach this goal. Transfer functions have been implemented to fit SCA and Jaya to the discontinuous nature of the bridge optimization problem. Furthermore, a Design of Experiments has been conducted to tune the algorithm and set its parameters. Consequently, it has been observed that SCA shows similar values for objective cost function as SAMO2 but improves computational time by 18% while also getting lower values for the objective function result deviation. From a cost and CO¿ optimization analysis, it has been observed that a reduction of 2.51 kg CO¿ is obtained by each euro reduced using metaheuristic techniques. Moreover, for both optimization objectives, it is observed that adding cells to bridge cross-sections improves not only the section behavior but also the optimization results. Finally, it is observed that the proposed design of double composite action in the supports allows this study to remove continuous longitudinal stiffeners in the bottom flange.