Stainless steel corrugated web girders for composite road bridges: Optimization and parametric studies

Artikel i vetenskaplig tidskrift, 2023

To achieve sustainability in bridge design, it is critical to ensure both economic viability and low environmental impact. While stainless steel has great mechanical properties and life cycle performance, the material is expensive, which has limited its use in bridges. This research aims at exploring the benefits of using stainless steel corrugated web girders as an alternative to carbon steel flat web girders in composite road bridges. This concept is expected to lower the investment cost, which enables a broader utilization of the good properties offered by stainless steel. A genetic algorithm optimization routine has been developed to produce bridge designs with minimum weight, investment cost, life cycle cost (LCC), or life cycle impact. Multiple parametric studies are conducted using a simply supported reference bridge. The optimal design solutions are compared for two main design alternatives: conventional S355 flat web girders and duplex (EN 1.4162) corrugated web girders. The parametric studies consider the effects of different design parameters, including the span length, available girder depth, average daily traffic (ADT) with the corresponding indicated number of heavy vehicles in the slow lane (Nobs), and the paint maintenance schedule, on the optimal solutions. Furthermore, a sensitivity analysis is carried out to analyse the impact of inflation and discount rates on the obtained results. The results show that the concept of stainless steel corrugated web girders offers significant potential LCC and environmental impact saving for the examined span lengths, particularly in the case of deeper girders, high ADTs, and more intensive maintenance activities. Also, despite the influence of inflation and discount rates on LCC results, the studied concept consistently demonstrated favorable results.