Otimização multiobjetivo de projeto de pontes e viadutos: estudo de caso (Multi-objective optimization for bridge and viaduct design: case study)

This article presents the application of the Multiple Objective Particle Swarm Optimization (MOPSO) method, enhanced with specifically tuned parameters using the Taguchi method, for optimizing bridge and viaduct designs. Unlike conventional approaches, the optimization in this study encompasses the entire structure rather than focusing solely on the deck. This approach is illustrated through case studies on two viaducts located in Atalaia and Mandaguaçu along the BR-376 highway in Paraná, Brazil. In Atalaia, the optimized solutions achieved reductions in construction costs by 10.5% to 22.7%, CO₂ emissions by 8.9% to 21.2%, and extended the design service life by 24.0% to 540.7%. Similarly, in Mandaguaçu, the optimizations resulted in cost reductions ranging from 9.1% to 23.2%, decreases in CO₂ emissions from 12.7% to 23.5%, and increases in the design service life by up to 540.7%. The study also revealed consistent patterns between the degrees of freedom and objective functions; specifically, larger cross-sectional dimensions tended to lower costs, while smaller dimensions were associated with reduced CO₂ emissions. These findings illustrate the real-world performance improvements afforded by the optimization process, which not only reduces the global cost per year of service compared to the original designs but also enhances economic and environmental performance, thereby demonstrating the effectiveness of MOPSO in structural optimization for sustainable infrastructure development.