Genetic Algorithms for the Dependability Assurance in the Design of a Long-Span Suspension Bridge

A long-span suspension bridge is a complex structural system that interacts with the surrounding environment and the users. The environmental actions and the corresponding loads (wind, temperature, rain, earthquake, etc.) together with the live loads (railway traffic, highway traffic), have a strong influence on the dynamic response of the bridge, and can significantly influence the structural behavior and alter its geometry, thus limiting the serviceability performance even up to a partial closure. This article will present some general considerations and operative aspects of the activities related to the analysis and design of such a complex structural system. Specific reference is made to the dependability assessment and the performance requirements of the whole system, while focus is given on methods for handling the completeness and the uncertainty in the assessment of the load scenarios. Aiming at the serviceability assessment, a method based on the combined application of genetic algorithms and a finite element method (FEM) investigation is proposed and applied.