Steel bridges — General design

The design of a bridge is a lengthy process of study aimed at reconciling various constraints, the importance and order of pre-eminence of which vary from project to project: natural data for the crossing, functional data for the roadway, construction procedures, integration into the environment, costs, deadlines... This article, a short guide to design and construction, is intended to provide designers with the basic elements they need to form their own judgement and acquire the thinking process specific to metal engineering structures. The solutions are based on the three main components of a bridge structure: the load-bearing system (beam, arch, cable suspension), the girder (solid web, box, truss) and the deck (concrete, steel, composite). The final part is devoted to the execution of the structure, the final goal of the project, but also an essential phase in the design process.