Life-Cycle Design of Steel-Concrete Composite Bridges

The current practice of bridge design generally focuses on optimizing the economic and performance aspects of the bridge construction. Hence, it does not enable to fully optimize the operation and end-of-life strategies. In particular, maintenance strategies may be different from one design solution to another and one solution can appear to be more attractive at the design stage but less interesting when the entire life-cycle is considered, all the more, when user costs are also considered in the decision process. For these reasons, a global life-cycle approach is proposed in this paper to provide the bridge owner with a complete comparison within a set of design solutions from the construction to the end-of-life. It aims at combining economic, environmental and societal during their service lifetime. Several design alternatives for steel-concrete composite bridges are given for illustration. The different stages of the global life-cycle analysis are presented and major results and conclusions are given. A multi-criteria decision analysis is also presented to highlight the comparison between alternatives.