Considerations for designing bridges for 100% utilisation to design standards

Sustainable construction aims to reduce the impact on the environment in construction processes, and civil engineers have an important role in achieving it. A key aspect of this is reducing the embodied carbon dioxide emissions in construction. Studies have shown that structural engineers design to a maximum utilisation of 80% and an average utilisation of 60%. One of the ways bridge engineers can achieve sustainable construction is by designing bridges closer to 100% utilisation of the available design standards, which will minimise the impact on the environment by using less materials. However, this rarely happens on projects for a variety of reasons that are not solely within the control of designers, and wider collaboration across client, contractor, designer and checker is required to enable it. This paper highlights the industry-wide challenges and considerations to be accounted for when designing for high utilisations and proposes solutions. The aim is firstly to equip designers with the knowledge to eliminate or mitigate potential risks on designing 100% utilisation; and secondly, to provide a framework amending procurement processes and contracts to ensure all designers tendering for work will aim to achieve a similar level of utilisation in their designs, levelling the playing field and maximising the design value.